Metamath Proof Explorer


Theorem 1p2e3ALT

Description: Alternate proof of 1p2e3 , shorter but using more axioms. (Contributed by David A. Wheeler, 8-Dec-2018) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Assertion 1p2e3ALT 1 + 2 = 3

Proof

Step Hyp Ref Expression
1 2cn 2
2 ax-1cn 1
3 2p1e3 2 + 1 = 3
4 1 2 3 addcomli 1 + 2 = 3