From f32ca304be7367ffe711d75db7e6c25750a37ac2 Mon Sep 17 00:00:00 2001
From: Dejan Nickovic <dejan.nickovic@ait.ac.at>
Date: Mon, 17 Feb 2025 18:12:40 +0100
Subject: [PATCH 1/4] Addition of the functionality to browse sub-signals +
 tests.

---
 .../ltl/discrete_time/explainer.py            | 74 +++++++++----------
 .../stl/discrete_time/explainer.py            | 10 +--
 ...tract_discrete_time_offline_interpreter.py |  2 +-
 ...stract_discrete_time_online_interpreter.py |  5 +-
 .../semantics/abstract_online_interpreter.py  |  7 ++
 rtamt/semantics/dense_time_interpreter.py     |  1 +
 .../stl/dense_time/offline/ast_visitor.py     |  5 ++
 .../stl/dense_time/online/ast_visitor.py      | 12 ++-
 .../dense_time/online/variable_operation.py   | 13 ++++
 .../stl/discrete_time/offline/ast_visitor.py  |  2 +-
 .../stl/discrete_time/online/ast_visitor.py   |  5 ++
 .../online/variable_operation.py              | 11 +++
 rtamt/spec/abstract_specification.py          | 14 +++-
 rtamt/spec/iastl/dense_time/specification.py  | 10 ++-
 .../syntax/ast/parser/abstract_ast_parser.py  |  8 +-
 rtamt/syntax/ast/parser/ltl/parser_visitor.py | 35 ++++++++-
 rtamt/syntax/ast/parser/stl/parser_visitor.py |  8 ++
 .../ast/visitor/abstract_ast_visitor.py       |  2 +-
 setup.py                                      |  2 +-
 .../api/test_browsing_monitoring_results.py   | 70 ++++++++++++++++++
 20 files changed, 241 insertions(+), 55 deletions(-)
 create mode 100644 rtamt/semantics/stl/dense_time/online/variable_operation.py
 create mode 100644 rtamt/semantics/stl/discrete_time/online/variable_operation.py
 create mode 100644 tests/python/api/test_browsing_monitoring_results.py

diff --git a/rtamt/explanation/ltl/discrete_time/explainer.py b/rtamt/explanation/ltl/discrete_time/explainer.py
index 19ef8dee..85a748e5 100644
--- a/rtamt/explanation/ltl/discrete_time/explainer.py
+++ b/rtamt/explanation/ltl/discrete_time/explainer.py
@@ -11,7 +11,7 @@ def __init__(self):
     def explain(self, spec):
         self.spec = spec
         for spec in self.spec.specs:
-            top_signal = self.spec.offline_results[spec]
+            top_signal = self.spec.results[spec]
             if top_signal[0] < 0:
                 self.visit(spec, [[[0, 0]], False])
 
@@ -23,8 +23,8 @@ def visitConstant(self, element, args):
     def visitPredicate(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         op1_intervals, op2_intervals = explain_predicate(op1_signal, op2_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -38,8 +38,8 @@ def visitVariable(self, element, args):
     def visitAddition(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         op1_intervals, op2_intervals = explain_addition(op1_signal, op2_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -49,8 +49,8 @@ def visitAddition(self, element, args):
     def visitMultiplication(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         op1_intervals, op2_intervals = explain_multiplication(op1_signal, op2_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -60,8 +60,8 @@ def visitMultiplication(self, element, args):
     def visitSubtraction(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         op1_intervals, op2_intervals = explain_subtraction(op1_signal, op2_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -71,8 +71,8 @@ def visitSubtraction(self, element, args):
     def visitDivision(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         op1_intervals, op2_intervals = explain_division(op1_signal, op2_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -82,7 +82,7 @@ def visitDivision(self, element, args):
     def visitAbs(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         op_intervals = explain_abs(op_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -91,7 +91,7 @@ def visitAbs(self, element, args):
     def visitSqrt(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         op_intervals = explain_sqrt(op_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -100,7 +100,7 @@ def visitSqrt(self, element, args):
     def visitExp(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         op_intervals = explain_exp(op_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -109,8 +109,8 @@ def visitExp(self, element, args):
     def visitPow(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         op1_intervals, op2_intervals = explain_pow(op1_signal, op2_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -120,7 +120,7 @@ def visitPow(self, element, args):
     def visitRise(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         op_intervals = explain_rise(op_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -129,7 +129,7 @@ def visitRise(self, element, args):
     def visitFall(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         op_intervals = explain_fall(op_signal, intervals)
         self.explanations[element.name] = intervals
 
@@ -138,7 +138,7 @@ def visitFall(self, element, args):
     def visitNot(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_not(op_signal, intervals)
         else:
@@ -150,8 +150,8 @@ def visitNot(self, element, args):
     def visitAnd(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         if flag:
             op1_intervals, op2_intervals = explain_sat_and(op1_signal, op2_signal, intervals)
         else:
@@ -164,8 +164,8 @@ def visitAnd(self, element, args):
     def visitOr(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         if flag:
             op1_intervals, op2_intervals = explain_sat_or(op1_signal, op2_signal, intervals)
         else:
@@ -178,8 +178,8 @@ def visitOr(self, element, args):
     def visitImplies(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         if flag:
             op1_intervals, op2_intervals = explain_sat_implies(op1_signal, op2_signal, intervals)
         else:
@@ -192,8 +192,8 @@ def visitImplies(self, element, args):
     def visitIff(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         if flag:
             op1_intervals, op2_intervals = explain_sat_iff(op1_signal, op2_signal, intervals)
         else:
@@ -206,8 +206,8 @@ def visitIff(self, element, args):
     def visitXor(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op1_signal = self.spec.offline_results[element.children[0]]
-        op2_signal = self.spec.offline_results[element.children[1]]
+        op1_signal = self.spec.results[element.children[0]]
+        op2_signal = self.spec.results[element.children[1]]
         if flag:
             op1_intervals, op2_intervals = explain_sat_xor(op1_signal, op2_signal, intervals)
         else:
@@ -220,7 +220,7 @@ def visitXor(self, element, args):
     def visitEventually(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_eventually(op_signal, intervals)
         else:
@@ -232,7 +232,7 @@ def visitEventually(self, element, args):
     def visitAlways(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_always(op_signal, intervals)
         else:
@@ -248,7 +248,7 @@ def visitUntil(self, element, args):
     def visitOnce(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_once(op_signal, intervals)
         else:
@@ -260,7 +260,7 @@ def visitOnce(self, element, args):
     def visitPrevious(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_prev(op_signal, intervals)
         else:
@@ -272,7 +272,7 @@ def visitPrevious(self, element, args):
     def visitStrongPrevious(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_prev(op_signal, intervals)
         else:
@@ -284,7 +284,7 @@ def visitStrongPrevious(self, element, args):
     def visitNext(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_next(op_signal, intervals)
         else:
@@ -296,7 +296,7 @@ def visitNext(self, element, args):
     def visitStrongNext(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_next(op_signal, intervals)
         else:
@@ -308,7 +308,7 @@ def visitStrongNext(self, element, args):
     def visitHistorically(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_historically(op_signal, intervals)
         else:
diff --git a/rtamt/explanation/stl/discrete_time/explainer.py b/rtamt/explanation/stl/discrete_time/explainer.py
index b7388008..5fb9b64f 100644
--- a/rtamt/explanation/stl/discrete_time/explainer.py
+++ b/rtamt/explanation/stl/discrete_time/explainer.py
@@ -17,14 +17,14 @@ def visit(self, element, args):
     def explain(self, spec):
         self.spec = spec
         for spec in self.spec.specs:
-            top_signal = self.spec.offline_results[spec]
+            top_signal = self.spec.results[spec]
             if top_signal[0] < 0:
                 self.visit(spec, [[[0,0]], False])
 
     def visitTimedEventually(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_timed_eventually(op_signal, intervals, element.begin, element.end)
         else:
@@ -35,7 +35,7 @@ def visitTimedEventually(self, element, args):
     def visitTimedAlways(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_timed_always(op_signal, intervals, element.begin, element.end)
         else:
@@ -49,7 +49,7 @@ def visitTimedUntil(self, element, args):
     def visitTimedOnce(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_timed_once(op_signal, intervals, element.begin, element.end)
         else:
@@ -60,7 +60,7 @@ def visitTimedOnce(self, element, args):
     def visitTimedHistorically(self, element, args):
         intervals = args[0]
         flag = args[1]
-        op_signal = self.spec.offline_results[element.children[0]]
+        op_signal = self.spec.results[element.children[0]]
         if flag:
             op_intervals = explain_sat_timed_historically(op_signal, intervals, element.begin, element.end)
         else:
diff --git a/rtamt/semantics/abstract_discrete_time_offline_interpreter.py b/rtamt/semantics/abstract_discrete_time_offline_interpreter.py
index c4ee770c..8b3ec240 100644
--- a/rtamt/semantics/abstract_discrete_time_offline_interpreter.py
+++ b/rtamt/semantics/abstract_discrete_time_offline_interpreter.py
@@ -29,7 +29,7 @@ def evaluate(self, dataset):
 
         # evaluate spec forest
         length = len(dataset['time'])
-        self.ast.offline_results['time'] = dataset['time']
+        self.ast.results['time'] = dataset['time']
 
         rob = self.visitAst(self.ast, length)
         rob = rob[len(rob)-1]
diff --git a/rtamt/semantics/abstract_discrete_time_online_interpreter.py b/rtamt/semantics/abstract_discrete_time_online_interpreter.py
index 69cd8ff6..cefebd26 100644
--- a/rtamt/semantics/abstract_discrete_time_online_interpreter.py
+++ b/rtamt/semantics/abstract_discrete_time_online_interpreter.py
@@ -18,7 +18,7 @@ def __init__(self):
     # inputs - list of [var name, var value] pairs
     # Example:
     # update(1, [['a', 2.2], ['b', 3.3]])
-    #TODO merge dense and discrete into update AbstractOnlineInterpreter
+    # TODO merge dense and discrete into update AbstractOnlineInterpreter
     def update(self, timestamp, dataset):
         # check ast exists
         self.exist_ast()
@@ -29,6 +29,8 @@ def update(self, timestamp, dataset):
         # evaluate spec forest
         rob = self.updateVisitor.visitAst(self.ast, self.online_operator_dict, self.ast.var_object_dict)
         rob = rob[len(rob) - 1]
+        self.ast.results = self.updateVisitor.results
+
 
         out = self.ast.var_object_dict[self.ast.out_var]
         if self.ast.out_var_field:
@@ -60,6 +62,7 @@ def set_variable_to_ast_from_dataset(self, dataset):
             var_name = data[0]
             var_value = data[1]
             self.ast.var_object_dict[var_name] = var_value
+            self.online_operator_dict[var_name].sample = var_value
 
     @property
     def update_counter(self):
diff --git a/rtamt/semantics/abstract_online_interpreter.py b/rtamt/semantics/abstract_online_interpreter.py
index fdbe849f..c594eef5 100644
--- a/rtamt/semantics/abstract_online_interpreter.py
+++ b/rtamt/semantics/abstract_online_interpreter.py
@@ -60,9 +60,13 @@ def visitLeaf(self, node, online_operator_dict):
 
 
 class AbstractOnlineUpdateVisitor(AbstractAstVisitor):
+    def __init__(self):
+        self.results = dict()
+
     def visitSpec(self, node, online_operator_dict, var_object_dict):
         sample_return = self.visit(node, online_operator_dict, var_object_dict)
         var_object_dict[node] = sample_return  #TODO subspec name is necessary as a key for var_object_dict.
+        self.results[node] = sample_return
         return sample_return
 
     def visitBinary(self, node, online_operator_dict, var_object_dict):
@@ -70,12 +74,14 @@ def visitBinary(self, node, online_operator_dict, var_object_dict):
         sample_right = self.visit(node.children[1], online_operator_dict, var_object_dict)
         operator = online_operator_dict[node.name]
         sample_return = operator.update(sample_left, sample_right)
+        self.results[node] = sample_return
         return sample_return
 
     def visitUnary(self, node, online_operator_dict, var_object_dict):
         sample = self.visit(node.children[0], online_operator_dict, var_object_dict)
         op = online_operator_dict[node.name]
         sample_return = op.update(sample)
+        self.results[node] = sample_return
         return sample_return
 
     def visitLeaf(self, node, online_operator_dict, var_object_dict):
@@ -83,4 +89,5 @@ def visitLeaf(self, node, online_operator_dict, var_object_dict):
             sample_return = self.visitConstant(node, online_operator_dict, var_object_dict)
         elif isinstance(node, Variable):
             sample_return = self.visitVariable(node, online_operator_dict, var_object_dict)
+        self.results[node] = sample_return
         return sample_return
diff --git a/rtamt/semantics/dense_time_interpreter.py b/rtamt/semantics/dense_time_interpreter.py
index d4c51a81..db4caad7 100644
--- a/rtamt/semantics/dense_time_interpreter.py
+++ b/rtamt/semantics/dense_time_interpreter.py
@@ -20,6 +20,7 @@ def set_variable_to_ast_from_dataset(self, dataset):
             var_name = data[0]
             var_object = data[1]
             self.ast.var_object_dict[var_name] = var_object
+            self.online_operator_dict[var_name].sample = var_object
 
     def time_unit_transformer(self, node):
         b = node.begin
diff --git a/rtamt/semantics/stl/dense_time/offline/ast_visitor.py b/rtamt/semantics/stl/dense_time/offline/ast_visitor.py
index d06c6bcb..c6d9414f 100644
--- a/rtamt/semantics/stl/dense_time/offline/ast_visitor.py
+++ b/rtamt/semantics/stl/dense_time/offline/ast_visitor.py
@@ -283,6 +283,11 @@ def until_timed_operation(sample_left, sample_right, begin, end):
 
 class StlDenseTimeOfflineAstVisitor(StlAstVisitor):
 
+    def visit(self, node, *args, **kwargs):
+        result = super(StlDenseTimeOfflineAstVisitor, self).visit(node, *args, **kwargs)
+        self.ast.results[node] = result
+        return result
+
     def visitPredicate(self, node, *args, **kwargs):
         sample_left  = self.visit(node.children[0], *args, **kwargs)
         sample_right = self.visit(node.children[1], *args, **kwargs)
diff --git a/rtamt/semantics/stl/dense_time/online/ast_visitor.py b/rtamt/semantics/stl/dense_time/online/ast_visitor.py
index f27967ff..35f5c1dc 100644
--- a/rtamt/semantics/stl/dense_time/online/ast_visitor.py
+++ b/rtamt/semantics/stl/dense_time/online/ast_visitor.py
@@ -1,4 +1,4 @@
-
+from rtamt.semantics.stl.dense_time.online.variable_operation import VariableOperation
 from rtamt.syntax.ast.visitor.stl.ast_visitor import StlAstVisitor
 
 from rtamt.semantics.arithmetic.dense_time.online.addition_operation import AdditionOperation
@@ -27,6 +27,16 @@
 from rtamt.exception.exception import RTAMTException
 
 class StlDenseTimeOnlineAstVisitor(StlAstVisitor):
+
+    def visit(self, node, *args, **kwargs):
+        result = super(StlDenseTimeOnlineAstVisitor, self).visit(node, *args, **kwargs)
+        self.ast.results[node] = result
+        return result
+
+    def visitVariable(self, node, *args, **kwargs):
+        self.visitChildren(node, *args, **kwargs)
+        self.online_operator_dict[node.name] = VariableOperation(node.operator)
+
     def visitPredicate(self, node, *args, **kwargs):
         self.visitChildren(node, *args, **kwargs)
         self.online_operator_dict[node.name] = PredicateOperation(node.operator)
diff --git a/rtamt/semantics/stl/dense_time/online/variable_operation.py b/rtamt/semantics/stl/dense_time/online/variable_operation.py
new file mode 100644
index 00000000..87cf4a40
--- /dev/null
+++ b/rtamt/semantics/stl/dense_time/online/variable_operation.py
@@ -0,0 +1,13 @@
+
+from rtamt.semantics.abstract_dense_time_online_operation import AbstractDenseTimeOnlineOperation
+
+class VariableOperation(AbstractDenseTimeOnlineOperation):
+    def __init__(self):
+        self.val = None
+
+    def update(self, *args, **kargs):
+        return self.val
+
+    def update_final(self, *args, **kargs):
+        out = list()
+        return
diff --git a/rtamt/semantics/stl/discrete_time/offline/ast_visitor.py b/rtamt/semantics/stl/discrete_time/offline/ast_visitor.py
index 963eb3a8..60201e42 100644
--- a/rtamt/semantics/stl/discrete_time/offline/ast_visitor.py
+++ b/rtamt/semantics/stl/discrete_time/offline/ast_visitor.py
@@ -11,7 +11,7 @@ class StlDiscreteTimeOfflineAstVisitor(StlAstVisitor):
 
     def visit(self, node, *args, **kwargs):
         result = super(StlDiscreteTimeOfflineAstVisitor, self).visit(node, *args, **kwargs)
-        self.ast.offline_results[node] = result
+        self.ast.results[node] = result
         return result
 
     def visitPredicate(self, node, *args, **kwargs):
diff --git a/rtamt/semantics/stl/discrete_time/online/ast_visitor.py b/rtamt/semantics/stl/discrete_time/online/ast_visitor.py
index d670e594..17969271 100644
--- a/rtamt/semantics/stl/discrete_time/online/ast_visitor.py
+++ b/rtamt/semantics/stl/discrete_time/online/ast_visitor.py
@@ -1,4 +1,5 @@
 from rtamt.semantics.stl.discrete_time.online.strong_previous_operation import StrongPreviousOperation
+from rtamt.semantics.stl.discrete_time.online.variable_operation import VariableOperation
 from rtamt.syntax.ast.visitor.stl.ast_visitor import StlAstVisitor
 
 from rtamt.semantics.arithmetic.discrete_time.online.addition_operation import AdditionOperation
@@ -32,6 +33,10 @@
 
 class StlDiscreteTimeOnlineAstVisitor(StlAstVisitor):
 
+    def visitVariable(self, node, *args, **kwargs):
+        self.visitChildren(node, *args, **kwargs)
+        self.online_operator_dict[node.name] = VariableOperation()
+
     def visitPredicate(self, node, *args, **kwargs):
         self.visitChildren(node, *args, **kwargs)
         self.online_operator_dict[node.name] = PredicateOperation(node.operator)
diff --git a/rtamt/semantics/stl/discrete_time/online/variable_operation.py b/rtamt/semantics/stl/discrete_time/online/variable_operation.py
new file mode 100644
index 00000000..486ec76e
--- /dev/null
+++ b/rtamt/semantics/stl/discrete_time/online/variable_operation.py
@@ -0,0 +1,11 @@
+from rtamt.semantics.abstract_online_operation import AbstractOnlineOperation
+
+class VariableOperation(AbstractOnlineOperation):
+    def __init__(self):
+        self.sample = None
+
+    def reset(self):
+        pass
+
+    def update(self):
+        return self.sample
diff --git a/rtamt/spec/abstract_specification.py b/rtamt/spec/abstract_specification.py
index b0b8696b..c8463ed8 100644
--- a/rtamt/spec/abstract_specification.py
+++ b/rtamt/spec/abstract_specification.py
@@ -24,6 +24,7 @@ def __init__(self, ast):
         self.var_topic_dict = dict()
         self.free_vars = set()
         self.var_object_dict = dict()
+        self.phi_name_to_node_dict = dict()
 
         #TODO we need to move it to RTAMT4ROS as wrapper
         self.modules = dict()
@@ -48,8 +49,8 @@ def spec(self, spec):
     def add_var(self, var):
         self.ast.vars.add(var)
 
-    def get_value(self, var_name):
-        return self.ast.get_value(var_name)
+    def get_value(self, phi_name):
+        return self.ast.get_value(phi_name)
 
     def add_sub_spec(self, sub_spec):
         self.ast.add_sub_spec(sub_spec)
@@ -96,6 +97,15 @@ def var_object_dict(self, var_object_dict):
         self.__var_object_dict = var_object_dict
         self.ast.var_object_dict = self.var_object_dict
 
+    @property
+    def phi_name_to_node_dict(self):
+        return self.ast.phi_name_to_node_dict
+
+    @phi_name_to_node_dict.setter
+    def phi_name_to_node_dict(self, phi_name_to_node_dict):
+        self.__phi_name_to_node_dict = phi_name_to_node_dict
+        self.ast.phi_name_to_node_dict = self.phi_name_to_node_dict
+
     @property
     def free_vars(self):
         return self.ast.free_vars
diff --git a/rtamt/spec/iastl/dense_time/specification.py b/rtamt/spec/iastl/dense_time/specification.py
index 4f40743b..85e322bf 100644
--- a/rtamt/spec/iastl/dense_time/specification.py
+++ b/rtamt/spec/iastl/dense_time/specification.py
@@ -16,33 +16,41 @@ def IAStlOutputRobustnessDenseTimeOfflineSpecification():
     spec = AbstractOfflineSpecification(StlAst(), IAStlOutputRobustnessDenseTimeOfflineInterpreter())
     return spec
 
+
 def IAStlInputVacuityDenseTimeOfflineSpecification():
     spec = AbstractOfflineSpecification(StlAst(), IAStlInputVacuityDenseTimeOfflineInterpreter())
     return spec
 
+
 def IAStlInputRobustnessDenseTimeOfflineSpecification():
     spec = AbstractOfflineSpecification(StlAst(), IAStlInputRobustnessDenseTimeOfflineInterpreter())
     return spec
 
+
 def IAStlOutputVacuityDenseTimeOfflineSpecification():
     spec = AbstractOfflineSpecification(StlAst(), IAStlOutputVacuityDenseTimeOfflineInterpreter())
     return spec
 
+
 def IAStlOutputRobustnessDenseTimeOnlineSpecification():
     spec = AbstractOnlineSpecification(StlAst(), IAStlOutputRobustnessDenseTimeOnlineInterpreter(),
                                        pastifier=StlPastifier())
     return spec
 
+
 def IAStlInputVacuityDenseTimeOnlineSpecification():
     spec = AbstractOnlineSpecification(StlAst(), IAStlInputVacuityDenseTimeOnlineInterpreter(),
                                        pastifier=StlPastifier())
     return spec
 
+
 def IAStlInputRobustnessDenseTimeOnlineSpecification():
     spec = AbstractOnlineSpecification(StlAst(), IAStlInputRobustnessDenseTimeOnlineInterpreter(),
                                        pastifier=StlPastifier())
     return spec
 
+
 def IAStlOutputVacuityDenseTimeOnlineSpecification():
-    spec = AbstractOnlineSpecification(StlAst(), IAStlOutputVacuityDenseTimeOnlineInterpreter(), pastifier=StlPastifier())
+    spec = AbstractOnlineSpecification(StlAst(), IAStlOutputVacuityDenseTimeOnlineInterpreter(),
+                                       pastifier=StlPastifier())
     return spec
diff --git a/rtamt/syntax/ast/parser/abstract_ast_parser.py b/rtamt/syntax/ast/parser/abstract_ast_parser.py
index 7ab7ca3b..db5ca1ed 100644
--- a/rtamt/syntax/ast/parser/abstract_ast_parser.py
+++ b/rtamt/syntax/ast/parser/abstract_ast_parser.py
@@ -65,7 +65,8 @@ def __init__(self, antrlLexerType, antrlParserType, parserErrorListenerType = No
         self.var_io_dict = dict()
         self.const_type_dict = dict()
         self.const_val_dict = dict()
-        self.offline_results = dict()
+        self.results = dict()
+        self.phi_name_to_node_dict = dict()
 
         self.modules = dict()
 
@@ -201,8 +202,9 @@ def modules(self, modules):
     def add_var(self, var):
         self.vars.add(var)
 
-    def get_value(self, var_name):
-        return self.var_object_dict[var_name]
+    def get_value(self, phi_name):
+        node = self.phi_name_to_node_dict[phi_name]
+        return self.results[node]
 
     def add_sub_spec(self, sub_spec):
         self.modular_spec = self.modular_spec + sub_spec + '\n'
diff --git a/rtamt/syntax/ast/parser/ltl/parser_visitor.py b/rtamt/syntax/ast/parser/ltl/parser_visitor.py
index cb0d7ceb..7dbaef7f 100644
--- a/rtamt/syntax/ast/parser/ltl/parser_visitor.py
+++ b/rtamt/syntax/ast/parser/ltl/parser_visitor.py
@@ -46,6 +46,7 @@ def visitExprPredicate(self, ctx):
         child2 = self.visit(ctx.expression(1))
         op_type = self.str_to_op_type(ctx.comparisonOp().getText())
         node = Predicate(child1, child2, op_type)
+        self.phi_name_to_node_dict[node.name] = node
 
         return node
 
@@ -56,9 +57,11 @@ def visitExprId(self, ctx):
         if id in self.const_val_dict:
             val = self.const_val_dict[id]
             node = Constant(float(val))
+            self.phi_name_to_node_dict[node.name] = node
         # Identifier is either an input variable or a sub-formula
         elif id in self.var_subspec_dict:
                 node = self.var_subspec_dict[id]
+                self.phi_name_to_node_dict[node.name] = node
                 return node
         else:
             id_tokens = id.split('.')
@@ -91,6 +94,7 @@ def visitExprId(self, ctx):
 
             var_io = self.var_io_dict[id_head]
             node = Variable(id_head, id_tail, var_io)
+            self.phi_name_to_node_dict[node.name] = node
 
         return node
 
@@ -138,141 +142,167 @@ def visitExprAddition(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Addition(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprSubtraction(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Subtraction(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprMultiplication(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Multiplication(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprDivision(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Division(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprAbs(self, ctx):
         child = self.visit(ctx.expression())
         node = Abs(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprSqrt(self, ctx):
         child = self.visit(ctx.expression())
         node = Sqrt(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprExp(self, ctx):
         child = self.visit(ctx.expression())
         node = Exp(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprPow(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Pow(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprNot(self, ctx):
         child = self.visit(ctx.expression())
         node = Neg(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprRise(self, ctx):
         child = self.visit(ctx.expression())
         node = Rise(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprLiteral(self, ctx):
         val = float(ctx.literal().getText())
         node = Constant(val)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprFall(self, ctx):
         child = self.visit(ctx.expression())
         node = Fall(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprAnd(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Conjunction(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprOr(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Disjunction(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprImplies(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Implies(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprIff(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Iff(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprXor(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Xor(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprAlways(self, ctx):
         child = self.visit(ctx.expression())
         node = Always(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprEv(self, ctx):
         child = self.visit(ctx.expression())
         node = Eventually(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprPrevious(self, ctx):
         child = self.visit(ctx.expression())
         node = Previous(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprStrongPrevious(self, ctx):
         child = self.visit(ctx.expression())
         node = StrongPrevious(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprNext(self, ctx):
         child = self.visit(ctx.expression())
         node = Next(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprStrongNext(self, ctx):
         child = self.visit(ctx.expression())
         node = StrongNext(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExpreOnce(self, ctx):
         child = self.visit(ctx.expression())
         node = Once(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprHist(self, ctx):
         child = self.visit(ctx.expression())
         node = Historically(child)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprSince(self, ctx):
         child1 = self.visit(ctx.expression(0))
         child2 = self.visit(ctx.expression(1))
         node = Since(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprUntil(self, ctx):
@@ -281,6 +311,7 @@ def visitExprUntil(self, ctx):
         child2 = self.visit(ctx.expression(1))
 
         node = Until(child1, child2)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprUnless(self, ctx):
@@ -291,6 +322,7 @@ def visitExprUnless(self, ctx):
         left = Always(child1, 0, interval.end)
         right = Until(child1, child2)
         node = Disjunction(left, right)
+        self.phi_name_to_node_dict[node.name] = node
 
         return node
 
@@ -308,7 +340,8 @@ def visitAssertion(self, ctx):
             id = 'out'
             implicit = True
         else:
-            id = ctx.Identifier().getText();
+            id = ctx.Identifier().getText()
+        self.phi_name_to_node_dict[id] = out
 
         self.var_subspec_dict[id] = out
         id_tokens = id.split('.')
diff --git a/rtamt/syntax/ast/parser/stl/parser_visitor.py b/rtamt/syntax/ast/parser/stl/parser_visitor.py
index e7af24ca..9dc966c8 100644
--- a/rtamt/syntax/ast/parser/stl/parser_visitor.py
+++ b/rtamt/syntax/ast/parser/stl/parser_visitor.py
@@ -35,6 +35,7 @@ def visitExprAlways(self, ctx):
         else:
             interval = self.visit(ctx.interval())
             node = TimedAlways(child, interval)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
 
@@ -42,9 +43,11 @@ def visitExprEv(self, ctx):
         child = self.visit(ctx.expression())
         if ctx.interval() == None:
             node = Eventually(child)
+            self.phi_name_to_node_dict[node.name] = node
         else:
             interval = self.visit(ctx.interval())
             node = TimedEventually(child, interval)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExpreOnce(self, ctx):
@@ -54,6 +57,7 @@ def visitExpreOnce(self, ctx):
         else:
             interval = self.visit(ctx.interval())
             node = TimedOnce(child, interval)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprHist(self, ctx):
@@ -63,6 +67,7 @@ def visitExprHist(self, ctx):
         else:
             interval = self.visit(ctx.interval())
             node = TimedHistorically(child, interval)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprSince(self, ctx):
@@ -73,6 +78,7 @@ def visitExprSince(self, ctx):
         else:
             interval = self.visit(ctx.interval())
             node = TimedSince(child1, child2, interval)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprUntil(self, ctx):
@@ -83,6 +89,7 @@ def visitExprUntil(self, ctx):
         else:
             interval = self.visit(ctx.interval())
             node = TimedUntil(child1, child2, interval)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitExprUnless(self, ctx):
@@ -98,6 +105,7 @@ def visitExprUnless(self, ctx):
             left = TimedAlways(child1, interval_left)
             right = TimedUntil(child1, child2, interval)
             node = Disjunction(left, right)
+        self.phi_name_to_node_dict[node.name] = node
         return node
 
     def visitConstantTimeLiteral(self, ctx):
diff --git a/rtamt/syntax/ast/visitor/abstract_ast_visitor.py b/rtamt/syntax/ast/visitor/abstract_ast_visitor.py
index 3bb917db..ad5bdcf6 100644
--- a/rtamt/syntax/ast/visitor/abstract_ast_visitor.py
+++ b/rtamt/syntax/ast/visitor/abstract_ast_visitor.py
@@ -14,7 +14,7 @@ def visitChildren(self, node, *args, **kwargs):
         result = None
         for nodeChild in node.children:
             result = self.visit(nodeChild, *args, **kwargs)
-        return result   # visitChildren reterns only last result
+        return result   # visitChildren returns only last result
 
     def visit(self, node, *args, **kwargs):
         if isinstance(node, BinaryNode):
diff --git a/setup.py b/setup.py
index 1b5922e2..3ad7db12 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@
 
 setup(
     name='rtamt',
-    version='0.4.6',
+    version='0.4.7',
     description='Library for specification-based online monitoring.',
     long_description=long_description,
     long_description_content_type="text/markdown",
diff --git a/tests/python/api/test_browsing_monitoring_results.py b/tests/python/api/test_browsing_monitoring_results.py
new file mode 100644
index 00000000..c3cd6dd1
--- /dev/null
+++ b/tests/python/api/test_browsing_monitoring_results.py
@@ -0,0 +1,70 @@
+import unittest
+
+from rtamt.spec.stl.discrete_time.specification import StlDiscreteTimeOfflineSpecification
+from rtamt.spec.stl.dense_time.specification import StlDenseTimeOfflineSpecification
+from rtamt.spec.stl.discrete_time.specification import StlDiscreteTimeOnlineSpecification
+from rtamt.spec.stl.dense_time.specification import StlDenseTimeOnlineSpecification
+
+
+class TestBrowsing(unittest.TestCase):
+
+    def __init__(self, *args, **kwargs):
+        super(TestBrowsing, self).__init__(*args, **kwargs)
+
+
+    def test_get_value_offline_dt(self):
+        spec = StlDiscreteTimeOfflineSpecification()
+        spec.declare_var('a', 'float')
+        spec.declare_var('b', 'float')
+        spec.declare_var('c', 'float')
+        spec.declare_var('d', 'float')
+        spec.spec = 'c = always(a>=2 and b<=3) d = always(b<=5)'
+        spec.parse()
+
+        dataset = {
+            'time': [0, 1, 2, 3, 4],
+            'a': [100, -1, -2, 5, -1],
+            'b': [50, 4, 7, 8, 0]
+        }
+        spec.evaluate(dataset)
+        a = spec.get_value('a')
+        b = spec.get_value('b')
+        c = spec.get_value('c')
+        d = spec.get_value('d')
+        conj = spec.get_value('((a)>=(2.0))and((b)<=(3.0))')
+        pred = spec.get_value('(a)>=(2.0)')
+
+        self.assertListEqual(a, [100, -1, -2, 5, -1])
+        self.assertListEqual(b, [50, 4, 7, 8, 0])
+        self.assertListEqual(c, [-47, -5, -5, -5, -3])
+        self.assertListEqual(d, [-45, -3, -3, -3, 5])
+        self.assertListEqual(conj, [-47, -3, -4, -5, -3])
+        self.assertListEqual(pred, [98, -3, -4, 3, -3])
+
+    def test_get_value_online_dt(self):
+        spec = StlDiscreteTimeOnlineSpecification()
+        spec.declare_var('a', 'float')
+        spec.declare_var('b', 'float')
+        spec.declare_var('c', 'float')
+        spec.declare_var('d', 'float')
+        spec.spec = 'c = (a>=2 and b<=3) d = (b<=5)'
+        spec.parse()
+
+        spec.update(0, [('a', 100), ('b', 50)])
+        spec.update(1, [('a', -1), ('b', 4)])
+        a = spec.get_value('a')
+        b = spec.get_value('b')
+        c = spec.get_value('c')
+        d = spec.get_value('d')
+        conj = spec.get_value('((a)>=(2.0))and((b)<=(3.0))')
+        pred = spec.get_value('(a)>=(2.0)')
+
+        self.assertEqual(a, -1)
+        self.assertEqual(b, 4)
+        self.assertEqual(c, -3)
+        self.assertEqual(d, 1)
+        self.assertEqual(conj, -3)
+        self.assertEqual(pred, -3)
+
+if __name__ == '__main__':
+    unittest.main()
\ No newline at end of file

From 8c2a5680013e3da28cff1a04b6cc81689e5f9b08 Mon Sep 17 00:00:00 2001
From: nickovic <dejan.nickovic@ait.ac.at>
Date: Wed, 19 Feb 2025 20:10:30 +0100
Subject: [PATCH 2/4] Completed the browsing functionality.

---
 .../abstract_dense_time_online_interpreter.py |  9 +++
 ...stract_discrete_time_online_interpreter.py |  5 +-
 rtamt/semantics/dense_time_interpreter.py     | 11 +++-
 .../stl/dense_time/online/ast_visitor.py      |  2 +-
 rtamt/spec/abstract_specification.py          |  6 +-
 .../api/test_browsing_monitoring_results.py   | 55 +++++++++++++++++++
 .../api/test_stl_sampling_time_units.py       | 10 ++--
 7 files changed, 86 insertions(+), 12 deletions(-)

diff --git a/rtamt/semantics/abstract_dense_time_online_interpreter.py b/rtamt/semantics/abstract_dense_time_online_interpreter.py
index 151a0366..a100f67c 100644
--- a/rtamt/semantics/abstract_dense_time_online_interpreter.py
+++ b/rtamt/semantics/abstract_dense_time_online_interpreter.py
@@ -35,6 +35,8 @@ def update(self, dataset):
         rob = self.updateVisitor.visitAst(self.ast, self.online_operator_dict, self.ast.var_object_dict)
         rob = rob[len(rob) - 1]
 
+        self.ast.results = self.updateVisitor.results
+
         out = self.ast.var_object_dict[self.ast.out_var]
         if self.ast.out_var_field:
             setattr(out, self.ast.out_var_field, rob)
@@ -57,6 +59,13 @@ def update_final(self, dataset):
 
         return rob
 
+    def set_variable_to_ast_from_dataset(self, dataset):
+        for data in dataset:
+            var_name = data[0]
+            var_object = data[1]
+            if data[0] in self.ast.free_vars:
+                self.ast.var_object_dict[var_name] = var_object
+                self.online_operator_dict[var_name].sample = var_object
 
 class DenseTimeOnlineUpdateVisitor(AbstractOnlineUpdateVisitor):
     def visitVariable(self, node, online_operator_dict, var_object_dict):
diff --git a/rtamt/semantics/abstract_discrete_time_online_interpreter.py b/rtamt/semantics/abstract_discrete_time_online_interpreter.py
index cefebd26..afa959db 100644
--- a/rtamt/semantics/abstract_discrete_time_online_interpreter.py
+++ b/rtamt/semantics/abstract_discrete_time_online_interpreter.py
@@ -61,8 +61,9 @@ def set_variable_to_ast_from_dataset(self, dataset):
         for data in dataset:
             var_name = data[0]
             var_value = data[1]
-            self.ast.var_object_dict[var_name] = var_value
-            self.online_operator_dict[var_name].sample = var_value
+            if data[0] in self.ast.free_vars:
+                self.ast.var_object_dict[var_name] = var_value
+                self.online_operator_dict[var_name].sample = var_value
 
     @property
     def update_counter(self):
diff --git a/rtamt/semantics/dense_time_interpreter.py b/rtamt/semantics/dense_time_interpreter.py
index db4caad7..588d396b 100644
--- a/rtamt/semantics/dense_time_interpreter.py
+++ b/rtamt/semantics/dense_time_interpreter.py
@@ -19,8 +19,15 @@ def set_variable_to_ast_from_dataset(self, dataset):
         for data in dataset:
             var_name = data[0]
             var_object = data[1]
-            self.ast.var_object_dict[var_name] = var_object
-            self.online_operator_dict[var_name].sample = var_object
+            if data[0] in self.ast.free_vars:
+                self.ast.var_object_dict[var_name] = var_object
+
+    def is_dataset_valid(self, dataset):
+        dataset_vars = set()
+        for data in dataset:
+            dataset_vars.add(data[0])
+        valid = dataset_vars == self.ast.free_vars
+        return valid
 
     def time_unit_transformer(self, node):
         b = node.begin
diff --git a/rtamt/semantics/stl/dense_time/online/ast_visitor.py b/rtamt/semantics/stl/dense_time/online/ast_visitor.py
index 35f5c1dc..367615da 100644
--- a/rtamt/semantics/stl/dense_time/online/ast_visitor.py
+++ b/rtamt/semantics/stl/dense_time/online/ast_visitor.py
@@ -35,7 +35,7 @@ def visit(self, node, *args, **kwargs):
 
     def visitVariable(self, node, *args, **kwargs):
         self.visitChildren(node, *args, **kwargs)
-        self.online_operator_dict[node.name] = VariableOperation(node.operator)
+        self.online_operator_dict[node.name] = VariableOperation()
 
     def visitPredicate(self, node, *args, **kwargs):
         self.visitChildren(node, *args, **kwargs)
diff --git a/rtamt/spec/abstract_specification.py b/rtamt/spec/abstract_specification.py
index c8463ed8..e0c3be94 100644
--- a/rtamt/spec/abstract_specification.py
+++ b/rtamt/spec/abstract_specification.py
@@ -10,6 +10,10 @@
 
 from rtamt.exception.exception import RTAMTException
 
+from antlr4 import *
+from antlr4.InputStream import InputStream
+from antlr4.error.ErrorListener import ErrorListener
+
 
 class AbstractSpecification(object):
     __metaclass__ = ABCMeta
@@ -300,8 +304,6 @@ def update(self, *args, **kwargs):
             i = args[0]
             dataset = args[1]
             return self.online_interpreter.update(i, dataset)
-        else:
-            pass
 
     def final_update(self, *args, **kwargs):
         if self.set_ast_flag != True:
diff --git a/tests/python/api/test_browsing_monitoring_results.py b/tests/python/api/test_browsing_monitoring_results.py
index c3cd6dd1..ad67c20c 100644
--- a/tests/python/api/test_browsing_monitoring_results.py
+++ b/tests/python/api/test_browsing_monitoring_results.py
@@ -66,5 +66,60 @@ def test_get_value_online_dt(self):
         self.assertEqual(conj, -3)
         self.assertEqual(pred, -3)
 
+    def test_get_value_offline_ct(self):
+        spec = StlDenseTimeOfflineSpecification()
+        spec.declare_var('a', 'float')
+        spec.declare_var('b', 'float')
+        spec.declare_var('c', 'float')
+        spec.spec = 'c = a and b'
+        spec.parse()
+
+        left = [[0, 1.3], [0.7, 3], [1.3, 0.1], [2.1, -2.2]]
+        right = [[0, 2.5], [0.7, 4], [1.3, -1.2], [2.1, 1.7]]
+
+        expected = [[0, 1.3], [0.7, 3], [1.3, -1.2], [2.1, -2.2]]
+
+        spec.evaluate(['a', left], ['b', right])
+        a = spec.get_value('a')
+        b = spec.get_value('b')
+        c = spec.get_value('c')
+        conj = spec.get_value('(a)and(b)')
+
+        self.assertListEqual(a, left)
+        self.assertListEqual(b, right)
+        self.assertListEqual(c, expected)
+        self.assertListEqual(conj, expected)
+
+    def test_get_value_online_ct(self):
+        spec = StlDenseTimeOnlineSpecification()
+        spec.declare_var('a', 'float')
+        spec.declare_var('b', 'float')
+        spec.declare_var('c', 'float')
+        spec.spec = 'c = a and b'
+
+        spec.parse()
+
+        in_data_1_1 = [[2, 2], [3.3, 3], [5.7, 4]]
+        in_data_2_1 = [[2.5, 5], [4.7, 6]]
+
+        in_data_1_2 = []
+        in_data_2_2 = [[5.7, 1]]
+
+        out_expected_1 = [[2.5, 2], [3.3, 3], [4.7, 3]]
+        out_expected_2 = [[5.7, 1]]
+
+        spec.update(['a', in_data_1_1], ['b', in_data_2_1])
+        spec.update(['a', in_data_1_2], ['b', in_data_2_2])
+
+        a = spec.get_value('a')
+        b = spec.get_value('b')
+        c = spec.get_value('c')
+        conj = spec.get_value('(a)and(b)')
+
+        self.assertListEqual(a, in_data_1_2)
+        self.assertListEqual(b, in_data_2_2)
+        self.assertListEqual(c, out_expected_2)
+        self.assertListEqual(conj, out_expected_2)
+
 if __name__ == '__main__':
     unittest.main()
\ No newline at end of file
diff --git a/tests/python/api/test_stl_sampling_time_units.py b/tests/python/api/test_stl_sampling_time_units.py
index 582ba1d9..da009d15 100755
--- a/tests/python/api/test_stl_sampling_time_units.py
+++ b/tests/python/api/test_stl_sampling_time_units.py
@@ -53,11 +53,11 @@ def test_default_unit_default_sampling_unit_greater_tolerance_ok_samples(self):
 
         try:
             spec.parse()
-            spec.update(0, [['req', 2.2], ['gnt', 1]])
-            spec.update(1.11, [['req', 2.2], ['gnt', 1]])
-            spec.update(1.99, [['req', 2.2], ['gnt', 1]])
-            spec.update(3.38, [['req', 2.2], ['gnt', 1]])
-            spec.update(4.39, [['req', 2.2], ['gnt', 1]])
+            spec.update(0, [['req', 2.2]])
+            spec.update(1.11, [['req', 2.2]])
+            spec.update(1.99, [['req', 2.2]])
+            spec.update(3.38, [['req', 2.2]])
+            spec.update(4.39, [['req', 2.2]])
 
             self.assertEqual(0, spec.sampling_violation_counter, 'Violation counter')
         except rtamt.RTAMTException as err:

From 44593e76e01aa960363502d67f68b430319d5e5a Mon Sep 17 00:00:00 2001
From: nickovic <dejan.nickovic@ait.ac.at>
Date: Wed, 19 Feb 2025 20:14:39 +0100
Subject: [PATCH 3/4] Tests with python 3.8 only

---
 .github/workflows/ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f8d592ab..1325d391 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python-version: [3.7, 3.8]
+        python-version: [3.8]
 
     steps:
     - uses: actions/checkout@v1

From 5ac3ddf89d481c8c70eb97a620f31ec329a9ac35 Mon Sep 17 00:00:00 2001
From: nickovic <dejan.nickovic@ait.ac.at>
Date: Wed, 19 Feb 2025 20:42:48 +0100
Subject: [PATCH 4/4] Added the description of the get_value() method to README
 and an example to the examples folder.

---
 README.md                                     | 48 +++++++++++++++++++
 .../access_subformulas/access_subformulas.py  | 43 +++++++++++++++++
 .../syntax/ast/parser/abstract_ast_parser.py  |  1 +
 3 files changed, 92 insertions(+)
 create mode 100644 examples/features/access_subformulas/access_subformulas.py

diff --git a/README.md b/README.md
index 2ac20183..8fa39ca3 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,8 @@
   - [Dense-time Offline Monitor](#dense-time-offline-monitor)
   - [Discrete-time Specifics](#discrete-time-specifics)
     - [Working with time units and timing assumptions](#working-with-time-units-and-timing-assumptions)
+- [Features]
+  - [Accessing evaluation of sub-formulas]
 - [References](#references)
 
 <!-- markdown-toc end -->
@@ -517,6 +519,52 @@ Finally, the following program is correct, because the temporal bound is explici
     spec.parse()
     ...
 ```
+# Features
+
+## Accessing evaluation of sub-formulas
+
+The following example shows how to use the `get_value` method from the 
+specification object to access the evaluated values of sub-formulas. This works for both 
+discrete- and dense-time specifications, as well as for online and offline 
+monitors.
+
+```python
+def monitor():
+    # data
+    dataset = {
+         'time': [0, 1, 2],
+         'a': [100.0, -1.0, -2.0],
+         'b': [20.0, 2.0, 10.0]
+    }
+
+    # # stl
+    spec = rtamt.StlDiscreteTimeSpecification()
+    spec.name = 'HandMadeMonitor'
+    spec.declare_var('a', 'float')
+    spec.declare_var('b', 'float')
+    spec.declare_var('c', 'float')
+    spec.declare_var('d', 'float')
+    spec.add_sub_spec('c = a + b')
+    spec.spec = 'd = c >= - 2'
+
+    try:
+        spec.parse()
+    except rtamt.RTAMTException as err:
+        print('RTAMT Exception: {}'.format(err))
+        sys.exit()
+
+    spec.evaluate(dataset)
+    a = spec.get_value('a')
+    b = spec.get_value('b')
+    c = spec.get_value('c')
+    d = spec.get_value('d')
+
+    print('a: ' + str(a))
+    print('b: ' + str(b))
+    print('c: ' + str(c))
+    print('d: ' + str(d))
+
+```
 
 # References
 
diff --git a/examples/features/access_subformulas/access_subformulas.py b/examples/features/access_subformulas/access_subformulas.py
new file mode 100644
index 00000000..8dc47654
--- /dev/null
+++ b/examples/features/access_subformulas/access_subformulas.py
@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+import sys
+import rtamt
+
+def monitor():
+    # data
+    dataset = {
+         'time': [0, 1, 2],
+         'a': [100.0, -1.0, -2.0],
+         'b': [20.0, 2.0, 10.0]
+    }
+
+    # # stl
+    spec = rtamt.StlDiscreteTimeSpecification()
+    spec.name = 'HandMadeMonitor'
+    spec.declare_var('a', 'float')
+    spec.declare_var('b', 'float')
+    spec.declare_var('c', 'float')
+    spec.declare_var('d', 'float')
+    spec.add_sub_spec('c = a + b')
+    spec.spec = 'd = c >= - 2'
+
+    try:
+        spec.parse()
+    except rtamt.RTAMTException as err:
+        print('RTAMT Exception: {}'.format(err))
+        sys.exit()
+
+    spec.evaluate(dataset)
+    a = spec.get_value('a')
+    b = spec.get_value('b')
+    c = spec.get_value('c')
+    d = spec.get_value('d')
+
+    print('a: ' + str(a))
+    print('b: ' + str(b))
+    print('c: ' + str(c))
+    print('d: ' + str(d))
+
+if __name__ == '__main__':
+    # Process arguments
+
+    monitor()
diff --git a/rtamt/syntax/ast/parser/abstract_ast_parser.py b/rtamt/syntax/ast/parser/abstract_ast_parser.py
index db5ca1ed..cdd19dcd 100644
--- a/rtamt/syntax/ast/parser/abstract_ast_parser.py
+++ b/rtamt/syntax/ast/parser/abstract_ast_parser.py
@@ -5,6 +5,7 @@
 from antlr4.InputStream import InputStream
 from antlr4.error.ErrorListener import ErrorListener
 
+from rtamt.syntax.ast.parser.stl.parser_visitor import StlAstParserVisitor
 from rtamt.exception.exception import RTAMTException
 
 class AbstractAst: