Results on the Propositional µ-Calculus

Abstrack In this paper we define and study a propositional p-calculur Lp, which consists essentialI) ol propositional modal logic with a least fixpoint operator. Lp is syntactically simpler yet strictly nwc exprcsk~e than Propositional Dqnamic Logic (PDL). For a rtxtrictcd version \\L‘ give an cuponcntinl-time decision procedure. small model prcqwty. and complete deductive system. thcri,, wbuming the corresponding results for PDL.