9085167872
This example is based on a Lean 3 issue described at https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/equation.20compiler.20help.20me.20plz
13 lines
343 B
Text
13 lines
343 B
Text
variable (F : Fin 4 → Type) (a : F 0 → F 1) (b : F 1 → F 2) (c : F 2 → F 3)
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def map : (i j : Fin 4) → (hij : i ≤ j) → F i → F j
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| 0, 0, _ => id
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| 1, 1, _ => id
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| 2, 2, _ => id
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| 3, 3, _ => id
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| 0, 1, _ => a
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| 0, 2, _ => b ∘ a
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| 0, 3, _ => c ∘ b ∘ a
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| 1, 2, _ => b
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| 1, 3, _ => c ∘ b
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| 2, 3, _ => c
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