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 )