Theorem 2m1e1

Description: 2 - 1 = 1. The result is on the right-hand-side to be consistent with similar proofs like 4p4e8 . (Contributed by David A. Wheeler, 4-Jan-2017)

	Ref	Expression
Assertion	2m1e1	$$⊢2-1=1$$

Proof

Step	Hyp	Ref	Expression
1		2cn	$$⊢2\in ℂ$$
2		ax-1cn	$$⊢1\in ℂ$$
3		1p1e2	$$⊢1+1=2$$
4	1 2 2 3	subaddrii	$$⊢2-1=1$$