41a2e9af19
This PR makes functions defined by well-founded recursion use an `opaque` well-founded proof by default. This reliably prevents kernel reduction of such definitions and proofs, which tends to be prohibitively slow (fixes #2171), and which regularly causes hard-to-debug kernel type-checking failures. This changes renders `unseal` ineffective for such definitions. To avoid the opaque proof, annotate the function definition with `@[semireducible]`.
24 lines
640 B
Text
24 lines
640 B
Text
@[semireducible]
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def fib (n : Nat) :=
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match n with
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| 0 | 1 => 1
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| x+2 => fib x + fib (x+1)
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termination_by n
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/--
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info: 89
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---
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info: [diag] Diagnostics
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[reduction] unfolded declarations (max: 407, num: 3):
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[reduction] Nat.rec ↦ 407
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[reduction] Or.rec ↦ 144
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[reduction] Acc.rec ↦ 108
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[reduction] unfolded reducible declarations (max: 352, num: 2):
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[reduction] Nat.casesOn ↦ 352
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[reduction] Or.casesOn ↦ 144
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use `set_option diagnostics.threshold <num>` to control threshold for reporting counters
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-/
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#guard_msgs in
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set_option diagnostics true in
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set_option diagnostics.threshold 100 in
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#reduce fib 10
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