Theorem 8p1e9 12307

Description: 8 + 1 = 9. (Contributed by Mario Carneiro, 18-Apr-2015.)

Assertion

Ref	Expression
8p1e9	⊢ (8 + 1) = 9

Proof of Theorem 8p1e9

Step	Hyp	Ref	Expression
1		df-9 12232	. 2 ⊢ 9 = (8 + 1)
2	1	eqcomi 2738	1 ⊢ (8 + 1) = 9

Syntax hints:   = wceq 1540  (class class class)co 7369  1c1 11045   + caddc 11047  8c8 12223  9c9 12224

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-9 2119  ax-ext 2701

This theorem depends on definitions:  df-bi 207  df-an 396  df-ex 1780  df-cleq 2721  df-9 12232

This theorem is referenced by:  cos2bnd  16132  19prm  17064  139prm  17070  317prm  17072  1259lem2  17078  1259lem4  17080  1259lem5  17081  1259prm  17082  2503lem1  17083  2503lem2  17084  2503lem3  17085  4001lem1  17087  quartlem1  26800  log2ub  26892  hgt750lem2  34636  lcmineqlem  42033  3lexlogpow5ineq2  42036  aks4d1p1  42057  sum9cubes  42653  3cubeslem3l  42667  3cubeslem3r  42668  fmtno5lem3  47549  fmtno5lem4  47550  fmtno4prmfac  47566  fmtno5fac  47576  139prmALT  47590  nfermltl8rev  47736  evengpop3  47792  bgoldbtbndlem1  47799