Axioms, invariants and guards can be marked as theorems. This means that the validity of the theorems must be proven from the axioms, invariants or guards declared before the theorem.
Sometimes an axiom/invariant/guard marked as theorem is also called a derived axiom/invariant/guard.
For an axiom , denotes (the conjunction of) all axioms declared in extended contexts and the axioms already declared in the current context before the axiom in question.
An axiom as theorem 

Name 
label/THM 
Goal 

For an invariant , denotes (the conjunction of) all the model’s invariants declared before the theorem.
An invariant as theorem 

Name 
label/THM 
Goal 

For a guard , denotes (the conjunction of) all the event’s guards declared before the theorem.
A guard as theorem 

Name 
label/THM 
Goal 
