Theorem typesafepets 39357

Description: Type-safe pets 39348 scheme. On a membership block-carrier 𝐴 ∈ MembParts, the lifted span (𝑅 ⋉ (^◡ E ↾ 𝐴)) yields a generalized partition of 𝐴 iff its coset relation yields an equivalence relation on the same carrier 𝐴. This is the type-safe replacement for the earlier broad pets 39348: it explicitly restricts to carriers where 𝐴 is already known to be a block-family (by MembParts). That removes the standard type-safety objection ("are you equating a quotient-carrier of blocks with raw witnesses?") by construction. It is the key bridge used to identify the partition-side and equivalence-side pet classes (petseq 39358), in complete parallel with the membership bridge mpets 39338. This theorem is intentionally not the definition of PetParts; it is the bridge used by petseq 39358 after typedness is enforced by the "Pet*" definitions. (Contributed by Peter Mazsa, 19-Feb-2026.)

Assertion

Ref	Expression
typesafepets	⊢ ((𝐴 ∈ MembParts ∧ 𝑅 ∈ 𝑉) → ((𝑅 ⋉ (◡ E ↾ 𝐴)) Parts 𝐴 ↔ ≀ (𝑅 ⋉ (◡ E ↾ 𝐴)) Ers 𝐴))

Proof of Theorem typesafepets

Step	Hyp	Ref	Expression
1		pets 39348	1 ⊢ ((𝐴 ∈ MembParts ∧ 𝑅 ∈ 𝑉) → ((𝑅 ⋉ (◡ E ↾ 𝐴)) Parts 𝐴 ↔ ≀ (𝑅 ⋉ (◡ E ↾ 𝐴)) Ers 𝐴))

Syntax hints:   → wi 4   ↔ wb 208   ∧ wa 397   ∈ wcel 2121   class class class wbr 5075   E cep 5520  ^◡ccnv 5620   ↾ cres 5623   ⋉ cxrn 38556   ≀ ccoss 38565   Ers cers 38590   Parts cparts 38605   MembParts cmembparts 38607

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-10 2154  ax-11 2170  ax-12 2191  ax-ext 2713  ax-rep 5202  ax-sep 5221  ax-nul 5231  ax-pow 5297  ax-pr 5365  ax-un 7682

This theorem depends on definitions:  df-bi 209  df-an 398  df-or 855  df-3an 1095  df-tru 1551  df-fal 1561  df-ex 1788  df-nf 1792  df-sb 2075  df-mo 2545  df-eu 2575  df-clab 2720  df-cleq 2733  df-clel 2816  df-nfc 2890  df-ne 2937  df-ral 3056  df-rex 3066  df-rmo 3346  df-rab 3394  df-v 3435  df-dif 3888  df-un 3890  df-in 3892  df-ss 3902  df-nul 4265  df-if 4458  df-pw 4534  df-sn 4559  df-pr 4561  df-op 4565  df-uni 4842  df-iun 4926  df-br 5076  df-opab 5138  df-mpt 5157  df-id 5516  df-eprel 5521  df-xp 5627  df-rel 5628  df-cnv 5629  df-co 5630  df-dm 5631  df-rn 5632  df-res 5633  df-ima 5634  df-iota 6445  df-fun 6491  df-fn 6492  df-f 6493  df-fo 6495  df-fv 6497  df-1st 7935  df-2nd 7936  df-ec 8639  df-qs 8643  df-xrn 38762  df-rels 38822  df-coss 38883  df-ssr 38960  df-refs 38972  df-refrels 38973  df-refrel 38974  df-cnvrefs 38987  df-cnvrefrels 38988  df-cnvrefrel 38989  df-syms 39004  df-symrels 39005  df-symrel 39006  df-trs 39038  df-trrels 39039  df-trrel 39040  df-eqvrels 39050  df-eqvrel 39051  df-dmqss 39104  df-dmqs 39105  df-ers 39130  df-erALTV 39131  df-funALTV 39149  df-disjss 39170  df-disjs 39171  df-disjALTV 39172  df-eldisj 39174  df-parts 39250  df-part 39251

This theorem is referenced by:  petseq  39358