Theorem rrgmex 14571

Description: A structure whose set of left-regular elements is inhabited is a set. (Contributed by Jim Kingdon, 12-Aug-2025.)

Hypothesis

Ref	Expression
rrgmex.e	⊢ 𝐸 = (RLReg‘𝑅)

Assertion

Ref	Expression
rrgmex	⊢ (𝐴 ∈ 𝐸 → 𝑅 ∈ V)

Proof of Theorem rrgmex

Dummy variables 𝑥 𝑟 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		mptrel 4908	. . . 4 ⊢ Rel (𝑟 ∈ V ↦ {𝑥 ∈ (Base‘𝑟) ∣ ∀𝑦 ∈ (Base‘𝑟)((𝑥(.r‘𝑟)𝑦) = (0g‘𝑟) → 𝑦 = (0g‘𝑟))})
2		df-rlreg 14568	. . . . 5 ⊢ RLReg = (𝑟 ∈ V ↦ {𝑥 ∈ (Base‘𝑟) ∣ ∀𝑦 ∈ (Base‘𝑟)((𝑥(.r‘𝑟)𝑦) = (0g‘𝑟) → 𝑦 = (0g‘𝑟))})
3	2	releqi 4858	. . . 4 ⊢ (Rel RLReg ↔ Rel (𝑟 ∈ V ↦ {𝑥 ∈ (Base‘𝑟) ∣ ∀𝑦 ∈ (Base‘𝑟)((𝑥(.r‘𝑟)𝑦) = (0g‘𝑟) → 𝑦 = (0g‘𝑟))}))
4	1, 3	mpbir 146	. . 3 ⊢ Rel RLReg
5		rrgmex.e	. . . . 5 ⊢ 𝐸 = (RLReg‘𝑅)
6	5	eleq2i 2305	. . . 4 ⊢ (𝐴 ∈ 𝐸 ↔ 𝐴 ∈ (RLReg‘𝑅))
7	6	biimpi 120	. . 3 ⊢ (𝐴 ∈ 𝐸 → 𝐴 ∈ (RLReg‘𝑅))
8		relelfvdm 5727	. . 3 ⊢ ((Rel RLReg ∧ 𝐴 ∈ (RLReg‘𝑅)) → 𝑅 ∈ dom RLReg)
9	4, 7, 8	sylancr 418	. 2 ⊢ (𝐴 ∈ 𝐸 → 𝑅 ∈ dom RLReg)
10	9	elexd 2835	1 ⊢ (𝐴 ∈ 𝐸 → 𝑅 ∈ V)

This proof depends on syntax axioms:   → wi 4   = wceq 1402   ∈ wcel 2209  ∀wral 2528  {crab 2532  Vcvv 2821   ↦ cmpt 4192  dom cdm 4774  Rel wrel 4779  ‘cfv 5377  (class class class)co 6085  Basecbs 13354  ._rcmulr 13434  0_gc0g 13612  RLRegcrlreg 14565

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4249  ax-pow 4311  ax-pr 4346

This proof depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ral 2533  df-rex 2534  df-v 2823  df-un 3224  df-in 3226  df-ss 3233  df-pw 3690  df-sn 3715  df-pr 3716  df-op 3718  df-uni 3936  df-br 4131  df-opab 4193  df-mpt 4194  df-xp 4780  df-rel 4781  df-dm 4784  df-iota 5337  df-fv 5385  df-rlreg 14568

This theorem is used by:  rrgval  14572