Theorem 3p1e4 8879

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 8805	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2144	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1332  (class class class)co 5782  1c1 7645   + caddc 7647  3c3 8796  4c4 8797

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 1424  ax-gen 1426  ax-ext 2122

This theorem depends on definitions:  df-bi 116  df-cleq 2133  df-4 8805

This theorem is referenced by:  7t6e42  9318  8t5e40  9323  9t5e45  9330  fac4  10511  4bc3eq4  10551  hash4  10592  cosq23lt0  12962