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Metamath Proof Explorer

Theorem 1e2m1

Description: 1 = 2 - 1. (Contributed by David A. Wheeler, 8-Dec-2018)

Ref Expression
Assertion 1e2m1 ⊢ 1 = 2 − 1

Proof

Step Hyp Ref Expression
1 2m1e1 ⊢ 2 − 1 = 1
2 1 eqcomi ⊢ 1 = 2 − 1