What makes a new ontology essential for today's theatre is the need for fundamental change in all aspects of this phenomenon. To respond to this need, side reforms do not help preserve theatre's status as a liberating art. This new ontology, addressed here as divergent theatre ontology, attempts to provide a new abstract intellectual framework for this issue before making any differences. To form such an ontology, mathematics can be used. In this method, mathematics can be used as an ideology framework. Considering that mathematical variables can be transferred from the field of symbology to the field of semantics, by turning into macro-theatre situations, each of the mathematical situations, allows the possibility to propose new hypotheses for theater by using mathematical theories.  This research aims to primarily present a specific form of an ontology of today's theatre as convergent theatre and to additionally express the new form using the mathematics of divergent theatre ontology and ultimately showing that any liberating aspect in theatre requires an infraction of the rules of convergent theatre and achieving some kind of divergence in theatre.