Metamath Proof Explorer


Theorem hsmex

Description: The collection of hereditarily size-limited well-founded sets comprise a set. The proof is that of Randall Holmes at http://math.boisestate.edu/~holmes/holmes/hereditary.pdf , with modifications to use Hartogs' theorem instead of the weak variant (inconsequentially weakening some intermediate results), and making the well-foundedness condition explicit to avoid a direct dependence on ax-reg . (Contributed by Stefan O'Rear, 14-Feb-2015)

Ref Expression
Assertion hsmex XVsR1On|xTCsxXV

Proof

Step Hyp Ref Expression
1 breq2 a=XxaxX
2 1 ralbidv a=XxTCsxaxTCsxX
3 2 rabbidv a=XsR1On|xTCsxa=sR1On|xTCsxX
4 3 eleq1d a=XsR1On|xTCsxaVsR1On|xTCsxXV
5 vex aV
6 eqid recdVhar𝒫a×dhar𝒫aω=recdVhar𝒫a×dhar𝒫aω
7 rdgeq2 e=brecfVfe=recfVfb
8 unieq f=cf=c
9 8 cbvmptv fVf=cVc
10 rdgeq1 fVf=cVcrecfVfb=reccVcb
11 9 10 ax-mp recfVfb=reccVcb
12 7 11 eqtrdi e=brecfVfe=reccVcb
13 12 reseq1d e=brecfVfeω=reccVcbω
14 13 cbvmptv eVrecfVfeω=bVreccVcbω
15 eqid sR1On|xTCsxa=sR1On|xTCsxa
16 eqid OrdIsoErankeVrecfVfeωzy=OrdIsoErankeVrecfVfeωzy
17 5 6 14 15 16 hsmexlem6 sR1On|xTCsxaV
18 4 17 vtoclg XVsR1On|xTCsxXV