Theorem 3p1e4 9321

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 9246	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2235	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1398  (class class class)co 6028  1c1 8076   + caddc 8078  3c3 9237  4c4 9238

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 1496  ax-gen 1498  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-cleq 2224  df-4 9246

This theorem is referenced by:  7t6e42  9767  8t5e40  9772  9t5e45  9779  fac4  11041  4bc3eq4  11081  hash4  11124  2exp16  13073  cosq23lt0  15627  binom4  15773