Linear temporal logic

It is a fragment of the more complex CTL*, which additionally allows branching time and quantifiers.

[4][5] LTL was first proposed for the formal verification of computer programs by Amir Pnueli in 1977.

An LTL formula can be satisfied by an infinite sequence of truth valuations of variables in AP.

These sequences can be viewed as a word on a path of a Kripke structure (an ω-word over alphabet 2AP).

This normal form allows R, true, false, and ∧ to appear in the formula, which are not fundamental operators of LTL.

Note that the transformation to the negation normal form does not blow up the length of the formula.

[11] Parametric linear temporal logic extends LTL with variables on the until-modality.