Theorem 3p1e4 9145

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 9070	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2200	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1364  (class class class)co 5925  1c1 7899   + caddc 7901  3c3 9061  4c4 9062

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 1461  ax-gen 1463  ax-ext 2178

This theorem depends on definitions:  df-bi 117  df-cleq 2189  df-4 9070

This theorem is referenced by:  7t6e42  9588  8t5e40  9593  9t5e45  9600  fac4  10844  4bc3eq4  10884  hash4  10925  2exp16  12633  cosq23lt0  15177  binom4  15323