Theorem 3p1e4 9057

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 8983	. 2 |- 4 = ( 3 + 1 )
2	1	eqcomi 2181	1 |- ( 3 + 1 ) = 4

Syntax hints:   = wceq 1353  (class class class)co 5878   1c1 7815   + caddc 7817   3c3 8974   4c4 8975

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 8983

This theorem is referenced by:  7t6e42  9499  8t5e40  9504  9t5e45  9511  fac4  10716  4bc3eq4  10756  hash4  10797  cosq23lt0  14442  binom4  14585