Theorem 3p1e4 9054

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 8980	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2181	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1353  (class class class)co 5875  1c1 7812   + caddc 7814  3c3 8971  4c4 8972

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 1447  ax-gen 1449  ax-ext 2159

This theorem depends on definitions:  df-bi 117  df-cleq 2170  df-4 8980

This theorem is referenced by:  7t6e42  9496  8t5e40  9501  9t5e45  9508  fac4  10713  4bc3eq4  10753  hash4  10794  cosq23lt0  14257  binom4  14400