Theorem 3p1e4 9278

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 9203	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2235	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1397  (class class class)co 6017  1c1 8032   + caddc 8034  3c3 9194  4c4 9195

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 1495  ax-gen 1497  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-cleq 2224  df-4 9203

This theorem is referenced by:  7t6e42  9722  8t5e40  9727  9t5e45  9734  fac4  10994  4bc3eq4  11034  hash4  11077  2exp16  13009  cosq23lt0  15556  binom4  15702