fix: finish? checks whether solver propagation steps are needed
#10949
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This PR ensures that solver propagation steps are necessary in the generated tactic script to close the goal. It produces more compact proof scripts, but this is not just an optimization, if we include an unnecessary step, we may fail to replay the generated script when `cases` steps are pruned using non-chronological backtracking (NCB). For example, when executing `finish?`, we may have performed a `cases #<anchor>` step that enabled `ring` to propagate a new fact. If this fact is not used in the final proof, and the corresponding `cases #<anchor>` step is pruned by NCB, the `ring` step will fail during replay.
wkrozowski
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Oct 27, 2025
…anprover#10949) This PR ensures that solver propagation steps are necessary in the generated tactic script to close the goal. It produces more compact proof scripts, but this is not just an optimization, if we include an unnecessary step, we may fail to replay the generated script when `cases` steps are pruned using non-chronological backtracking (NCB). For example, when executing `finish?`, we may have performed a `cases #<anchor>` step that enabled `ring` to propagate a new fact. If this fact is not used in the final proof, and the corresponding `cases #<anchor>` step is pruned by NCB, the `ring` step will fail during replay.
kim-em
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Oct 27, 2025
…0949) This PR ensures that solver propagation steps are necessary in the generated tactic script to close the goal. It produces more compact proof scripts, but this is not just an optimization, if we include an unnecessary step, we may fail to replay the generated script when `cases` steps are pruned using non-chronological backtracking (NCB). For example, when executing `finish?`, we may have performed a `cases #<anchor>` step that enabled `ring` to propagate a new fact. If this fact is not used in the final proof, and the corresponding `cases #<anchor>` step is pruned by NCB, the `ring` step will fail during replay.
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This PR ensures that solver propagation steps are necessary in the generated tactic script to close the goal.
It produces more compact proof scripts, but this is not just an optimization, if we include an unnecessary step, we may fail to replay the generated script when
casessteps are pruned using non-chronological backtracking (NCB). For example, when executingfinish?, we may have performed acases #<anchor>step that enabledringto propagate a new fact. If this fact is not used in the final proof, and the correspondingcases #<anchor>step is pruned by NCB, theringstep will fail during replay.