Theorem 9p1e10OLD 11159

Description: 9 + 1 = 10. (Contributed by Mario Carneiro, 18-Apr-2015.) Obsolete version of 9p1e10 11496 as of 8-Sep-2021. (New usage is discouraged.) (Proof modification is discouraged.)

Assertion

Ref	Expression
9p1e10OLD	⊢ (9 + 1) = 10

Proof of Theorem 9p1e10OLD

Step	Hyp	Ref	Expression
1		df-10OLD 11087	. 2 ⊢ 10 = (9 + 1)
2	1	eqcomi 2631	1 ⊢ (9 + 1) = 10

Syntax hints:   = wceq 1483  (class class class)co 6650  1c1 9937   + caddc 9939  9c9 11077  10c10 11078

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-ext 2602

This theorem depends on definitions:  df-bi 197  df-an 386  df-ex 1705  df-cleq 2615  df-10OLD 11087

This theorem is referenced by:  dfdecOLD  11495  declecOLD  11544  9p1e10bOLD  11556