Theorem submcld 18867

Description: Submonoids are closed under the monoid operation. (Contributed by Thierry Arnoux, 4-May-2025.)

Hypotheses

Ref	Expression
submcld.1	⊢ + = (+g‘𝑀)
submcld.2	⊢ (𝜑 → 𝑆 ∈ (SubMnd‘𝑀))
submcld.3	⊢ (𝜑 → 𝑋 ∈ 𝑆)
submcld.4	⊢ (𝜑 → 𝑌 ∈ 𝑆)

Assertion

Ref	Expression
submcld	⊢ (𝜑 → (𝑋 + 𝑌) ∈ 𝑆)

Proof of Theorem submcld

Step	Hyp	Ref	Expression
1		submcld.2	. 2 ⊢ (𝜑 → 𝑆 ∈ (SubMnd‘𝑀))
2		submcld.3	. 2 ⊢ (𝜑 → 𝑋 ∈ 𝑆)
3		submcld.4	. 2 ⊢ (𝜑 → 𝑌 ∈ 𝑆)
4		submcld.1	. . 3 ⊢ + = (+g‘𝑀)
5	4	submcl 18866	. 2 ⊢ ((𝑆 ∈ (SubMnd‘𝑀) ∧ 𝑋 ∈ 𝑆 ∧ 𝑌 ∈ 𝑆) → (𝑋 + 𝑌) ∈ 𝑆)
6	1, 2, 3, 5	syl3anc 1396	1 ⊢ (𝜑 → (𝑋 + 𝑌) ∈ 𝑆)

Syntax hints:   → wi 4   = wceq 1567   ∈ wcel 2149  ‘cfv 6533  (class class class)co 7408  +_gcplusg 17306  SubMndcsubmnd 18836

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-10 2182  ax-11 2198  ax-12 2219  ax-ext 2741  ax-sep 5258  ax-nul 5268  ax-pow 5334  ax-pr 5402

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1103  df-tru 1570  df-fal 1580  df-ex 1807  df-nf 1811  df-sb 2098  df-mo 2573  df-eu 2603  df-clab 2748  df-cleq 2761  df-clel 2844  df-nfc 2918  df-ne 2965  df-ral 3086  df-rex 3096  df-rab 3424  df-v 3465  df-dif 3916  df-un 3918  df-in 3920  df-ss 3930  df-nul 4295  df-if 4490  df-pw 4566  df-sn 4592  df-pr 4594  df-op 4598  df-uni 4874  df-br 5111  df-opab 5175  df-mpt 5194  df-id 5554  df-xp 5665  df-rel 5666  df-cnv 5667  df-co 5668  df-dm 5669  df-rn 5670  df-res 5671  df-ima 5672  df-iota 6489  df-fun 6535  df-fv 6541  df-ov 7411  df-submnd 18838

This theorem is referenced by:  ssdifidlprm  21451  gsumwun  33333  rloccring  33528  rlocisunit  33533