Theorem 3p1e4 9120

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 9045	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2197	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1364  (class class class)co 5919  1c1 7875   + caddc 7877  3c3 9036  4c4 9037

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 1458  ax-gen 1460  ax-ext 2175

This theorem depends on definitions:  df-bi 117  df-cleq 2186  df-4 9045

This theorem is referenced by:  7t6e42  9563  8t5e40  9568  9t5e45  9575  fac4  10807  4bc3eq4  10847  hash4  10888  cosq23lt0  15009  binom4  15152