Theorem 3p1e4 8855

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 8781	. 2 |- 4 = ( 3 + 1 )
2	1	eqcomi 2143	1 |- ( 3 + 1 ) = 4

Syntax hints:   = wceq 1331  (class class class)co 5774   1c1 7621   + caddc 7623   3c3 8772   4c4 8773

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 1423  ax-gen 1425  ax-ext 2121

This theorem depends on definitions:  df-bi 116  df-cleq 2132  df-4 8781

This theorem is referenced by:  7t6e42  9294  8t5e40  9299  9t5e45  9306  fac4  10479  4bc3eq4  10519  hash4  10560  cosq23lt0  12914