  This paper presents an ongoing work that is part of a more wide-ranging
project whose final scope is to define a method to validate LTL formulas w.r.t.
a program written in the timed concurrent constraint language tccp, which is a
logic concurrent constraint language based on the concurrent constraint
paradigm of Saraswat. Some inherent notions to tccp processes are
non-determinism, dealing with partial information in states and the monotonic
evolution of the information. In order to check an LTL property for a process,
our approach is based on the abstract diagnosis technique. The concluding step
of this technique needs to check the validity of an LTL formula (with
constraints) in an effective way.
  In this paper, we present a decision method for the validity of temporal
logic formulas (with constraints) built by our abstract diagnosis technique.
