Theorem 3p1e4 9048

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 8974	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2181	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1353  (class class class)co 5870  1c1 7807   + caddc 7809  3c3 8965  4c4 8966

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1447  ax-gen 1449  ax-ext 2159

This theorem depends on definitions:  df-bi 117  df-cleq 2170  df-4 8974

This theorem is referenced by:  7t6e42  9490  8t5e40  9495  9t5e45  9502  fac4  10704  4bc3eq4  10744  hash4  10785  cosq23lt0  14036  binom4  14179