Theorem 3p1e4 9117

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 9043	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2197	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1364  (class class class)co 5918  1c1 7873   + caddc 7875  3c3 9034  4c4 9035

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 9043

This theorem is referenced by:  7t6e42  9560  8t5e40  9565  9t5e45  9572  fac4  10804  4bc3eq4  10844  hash4  10885  cosq23lt0  14968  binom4  15111