Theorem 3p1e4 8541

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 8473	. 2 ⊢ 4 = (3 + 1)
2	1	eqcomi 2092	1 ⊢ (3 + 1) = 4

Syntax hints:   = wceq 1289  (class class class)co 5644  1c1 7341   + caddc 7343  3c3 8464  4c4 8465

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1381  ax-gen 1383  ax-ext 2070

This theorem depends on definitions:  df-bi 115  df-cleq 2081  df-4 8473

This theorem is referenced by:  7t6e42  8979  8t5e40  8984  9t5e45  8991  fac4  10129  4bc3eq4  10169  hash4  10210