9 lines
185 B
Text
9 lines
185 B
Text
import algebra.group
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open algebra
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variable {A : Type}
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variable [s : group A]
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include s
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theorem mul.right_inv (a : A) : a * a⁻¹ = 1 :=
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by rewrite [-{a}inv_inv at {1}, mul.left_inv]
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