Abstract: The tests for uncertain causal theory diagnoses are explored, the initial conditions for the test are generalized from true to any satisfactory A, the conception of test for uncertain precondition is proposed, several relevant theorems and their proofs are presented. The results in the paper can help one discriminate the space of candidate diagnoses and guarantee the preference order of the tests, and the effectiveness of testing is hence improved。

Key words: model-based diagnosis, uncertain causal theory, unc ertain test, uncertain precondition, discriminate