Theorem 3p1e4 8045

Description: 3 + 1 = 4. (Contributed by Mario Carneiro, 18-Apr-2015.)

Assertion

Ref	Expression
3p1e4	⊢ (3 + 1) = 4

Proof of Theorem 3p1e4

Step	Hyp	Ref	Expression
1		df-4 7975	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2044	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1243  (class class class)co 5512  1c1 6890   + caddc 6892  3c3 7965  4c4 7966

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-gen 1338  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-cleq 2033  df-4 7975

This theorem is referenced by:  7t6e42  8453  8t5e40  8458  9t5e45  8465