probability measure is set up in MV-algebra evaluation lattice and set of all propositions
and a probability truth degree of propositions in lattice-valued logic is proposed with integral.Thus pseudo-metric in set of all propositions is induced
probability logic metric space is established in lattice-valued logic
and graded reasoning is developed.In summary
approximate reasoning method in quantitative logic is expanded to lattice-valued logic
and it is feasible in graded in lattice-valued logic.