Theorem decex 12715

Description: A decimal number is a set. (Contributed by Mario Carneiro, 17-Apr-2015.) (Revised by AV, 6-Sep-2021.)

Assertion

Ref	Expression
decex	⊢ ;𝐴𝐵 ∈ V

Proof of Theorem decex

Step	Hyp	Ref	Expression
1		df-dec 12712	. 2 ⊢ ;𝐴𝐵 = (((9 + 1) · 𝐴) + 𝐵)
2	1	ovexi 7445	1 ⊢ ;𝐴𝐵 ∈ V

Syntax hints:   ∈ wcel 2149  Vcvv 3463  (class class class)co 7411  1c1 11101   + caddc 11103   · cmul 11105  9c9 12302  ;cdc 12711

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1822  ax-4 1836  ax-5 1937  ax-6 1994  ax-7 2035  ax-8 2151  ax-9 2159  ax-ext 2741  ax-nul 5271

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-tru 1570  df-fal 1580  df-ex 1807  df-sb 2098  df-clab 2748  df-cleq 2761  df-clel 2844  df-ne 2965  df-v 3465  df-dif 3916  df-un 3918  df-ss 3930  df-nul 4295  df-sn 4595  df-pr 4597  df-uni 4877  df-iota 6493  df-fv 6545  df-ov 7414  df-dec 12712

This theorem is referenced by:  nfermltl2rev  48431