CADiZ

Reference manual / Z-related commands / In situ replacement commands / disjunction


The disjunction command replaces logical predicates by equivalent predicates in disjunctive normal form, i.e. with disjunctions outermost. It also moves negations to be innermost. For disjunction to be applicable, the outermost operators of the logical predicate must be negations, conjunctions and disjunctions, in a combination that is not already in disjunctive normal form. Here is an example.

(p1 \lor p2) \land \lnot p3   \trarrow   p1 \land \lnot p3 \lor p2 \land \lnot p3

Tactic example

"disjunction" p4 p5

This example applies the disjunction command to predicates p4 and p5.


IT 2-Apr-1998