d3eca9fa35
We need this improvement to be able to finish Section "Other goodies" described at https://github.com/leanprover/lean/wiki/Refactoring-structures Before this commit, Lean would not be able to solve constraints such as ```lean @has_add.add nat nat.has_add a b =?= @had_add.add ?A ?inst a b ``` The problem is that projections were being reduced eagerly, and the constraint would be reduced to ```lean nat.add a b =?= @had_add.add ?A ?inst a b ``` The new test proj_uniy.lean contains similar unification problems.
66 lines
1.7 KiB
Text
66 lines
1.7 KiB
Text
open tactic
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-- Unify (prod.fst ?m) with (prod.fst (1,2))
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example : true :=
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by do
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type ← to_expr ``(nat × nat),
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m₁ ← mk_meta_var type,
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t₁ ← mk_app ``prod.fst [m₁],
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t₂ ← to_expr ``(prod.fst (1, 2)),
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unify t₁ t₂,
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constructor
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-- Unify (prod.fst (?m, 2)) with (prod.fst (3, 1))
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example : true :=
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by do
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type ← to_expr ``(nat),
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m₁ ← mk_meta_var type,
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two ← to_expr ``(2),
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mk ← mk_app ``prod.mk [m₁, two],
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t₁ ← mk_app ``prod.fst [mk],
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t₂ ← to_expr ``(prod.fst (3, 1)),
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trace t₁, trace t₂,
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unify t₁ t₂,
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four ← to_expr ``(4),
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fail_if_success (unify m₁ four),
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three ← to_expr ``(3),
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unify m₁ three,
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constructor
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-- Unify (prod.fst ?m) with (id (prod.fst (1,2)))
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example : true :=
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by do
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type ← to_expr ``(nat × nat),
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m₁ ← mk_meta_var type,
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t₁ ← mk_app ``prod.fst [m₁],
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t₂ ← to_expr ``(id (prod.fst (1, 2))),
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unify t₁ t₂,
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constructor
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-- Unify (id (prod.fst ?m)) with (prod.fst (1,2))
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example : true :=
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by do
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type ← to_expr ``(nat × nat),
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m₁ ← mk_meta_var type,
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s ← mk_app ``prod.fst [m₁],
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t₁ ← mk_app ``id [s],
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t₂ ← to_expr ``(id (prod.fst (1, 2))),
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unify t₁ t₂,
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constructor
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-- Unify (prod.fst (?m, 2)) with (id (prod.fst (3, 1)))
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example : true :=
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by do
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type ← to_expr ``(nat),
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m₁ ← mk_meta_var type,
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two ← to_expr ``(2),
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mk ← mk_app ``prod.mk [m₁, two],
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t₁ ← mk_app ``prod.fst [mk],
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t₂ ← to_expr ``(id (prod.fst (3, 1))),
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trace t₁, trace t₂,
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unify t₁ t₂,
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four ← to_expr ``(4),
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fail_if_success (unify m₁ four),
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three ← to_expr ``(3),
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unify m₁ three,
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constructor
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