Theorem decex 12643

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 12640	. 2 ⊢ ;𝐴𝐵 = (((9 + 1) · 𝐴) + 𝐵)
2	1	ovexi 7394	1 ⊢ ;𝐴𝐵 ∈ V

Syntax hints:   ∈ wcel 2121  Vcvv 3433  (class class class)co 7360  1c1 11034   + caddc 11036   · cmul 11038  9c9 12238  ;cdc 12639

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1803  ax-4 1817  ax-5 1918  ax-6 1975  ax-7 2016  ax-8 2123  ax-9 2131  ax-ext 2713  ax-nul 5231

This theorem depends on definitions:  df-bi 209  df-an 398  df-or 855  df-tru 1551  df-fal 1561  df-ex 1788  df-sb 2075  df-clab 2720  df-cleq 2733  df-clel 2816  df-ne 2937  df-v 3435  df-dif 3888  df-un 3890  df-ss 3902  df-nul 4265  df-sn 4559  df-pr 4561  df-uni 4842  df-iota 6445  df-fv 6497  df-ov 7363  df-dec 12640

This theorem is referenced by:  nfermltl2rev  48248