====== CAUS: Causality, Relation Between Cause and Effect ======

**Definition**: The statement ''(s1 CAUS s2)'' indicates that the situation ''s1'' (which must be real) is the cause for the situation ''s2'' (which must also be real). ''s2'' is the effect  actually brought about by ''s1''. The relation ''CAUS'' is transitive, asymmetric, and not reflexive.