Theorem 3p1e4 8992

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 8918	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2169	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1343  (class class class)co 5842  1c1 7754   + caddc 7756  3c3 8909  4c4 8910

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1435  ax-gen 1437  ax-ext 2147

This theorem depends on definitions:  df-bi 116  df-cleq 2158  df-4 8918

This theorem is referenced by:  7t6e42  9434  8t5e40  9439  9t5e45  9446  fac4  10646  4bc3eq4  10686  hash4  10727  cosq23lt0  13394  binom4  13537