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Theorem dfrdg2 4234
Description: Alternate definition of a recursive definition generator. (This was the original definition, but it was later replaced with the slightly shorter df-rdg 4233.)
Assertion
Ref Expression
dfrdg2 |- rec(F, A) = U.{f | E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y)))}
Distinct variable groups:   x,y,z,f,g,F   x,A,y,z,f,g

Proof of Theorem dfrdg2
StepHypRef Expression
1 df-rdg 4233 . 2 |- rec(F, A) = U.{f | E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y)))}
2 eqif 2431 . . . . . . . . . . . . . 14 |- (z = if(Lim dom g, U.ran g, (F` (g` U.dom g))) <-> ((Lim dom g /\ z = U.ran g) \/ (-. Lim dom g /\ z = (F` (g` U.dom g)))))
32anbi2i 483 . . . . . . . . . . . . 13 |- ((-. g = (/) /\ z = if(Lim dom g, U.ran g, (F` (g` U.dom g)))) <-> (-. g = (/) /\ ((Lim dom g /\ z = U.ran g) \/ (-. Lim dom g /\ z = (F` (g` U.dom g))))))
4 orcom 244 . . . . . . . . . . . . . 14 |- (((Lim dom g /\ z = U.ran g) \/ (-. Lim dom g /\ z = (F` (g` U.dom g)))) <-> ((-. Lim dom g /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g)))
54anbi2i 483 . . . . . . . . . . . . 13 |- ((-. g = (/) /\ ((Lim dom g /\ z = U.ran g) \/ (-. Lim dom g /\ z = (F` (g` U.dom g))))) <-> (-. g = (/) /\ ((-. Lim dom g /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))))
6 andi 607 . . . . . . . . . . . . . 14 |- ((-. g = (/) /\ ((-. Lim dom g /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))) <-> ((-. g = (/) /\ (-. Lim dom g /\ z = (F` (g` U.dom g)))) \/ (-. g = (/) /\ (Lim dom g /\ z = U.ran g))))
7 ioran 304 . . . . . . . . . . . . . . . . 17 |- (-. (g = (/) \/ Lim dom g) <-> (-. g = (/) /\ -. Lim dom g))
87anbi1i 484 . . . . . . . . . . . . . . . 16 |- ((-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) <-> ((-. g = (/) /\ -. Lim dom g) /\ z = (F` (g` U.dom g))))
9 anass 441 . . . . . . . . . . . . . . . 16 |- (((-. g = (/) /\ -. Lim dom g) /\ z = (F` (g` U.dom g))) <-> (-. g = (/) /\ (-. Lim dom g /\ z = (F` (g` U.dom g)))))
108, 9bitri 171 . . . . . . . . . . . . . . 15 |- ((-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) <-> (-. g = (/) /\ (-. Lim dom g /\ z = (F` (g` U.dom g)))))
11 dmeq 3402 . . . . . . . . . . . . . . . . . . . . 21 |- (g = (/) -> dom g = dom (/))
12 dm0 3414 . . . . . . . . . . . . . . . . . . . . 21 |- dom (/) = (/)
1311, 12syl6eq 1566 . . . . . . . . . . . . . . . . . . . 20 |- (g = (/) -> dom g = (/))
14 nlim0 3031 . . . . . . . . . . . . . . . . . . . . 21 |- -. Lim (/)
15 limeq 2987 . . . . . . . . . . . . . . . . . . . . 21 |- (dom g = (/) -> (Lim dom g <-> Lim (/)))
1614, 15mtbiri 722 . . . . . . . . . . . . . . . . . . . 20 |- (dom g = (/) -> -. Lim dom g)
1713, 16syl 10 . . . . . . . . . . . . . . . . . . 19 |- (g = (/) -> -. Lim dom g)
1817con2i 97 . . . . . . . . . . . . . . . . . 18 |- (Lim dom g -> -. g = (/))
1918pm4.71ri 641 . . . . . . . . . . . . . . . . 17 |- (Lim dom g <-> (-. g = (/) /\ Lim dom g))
2019anbi1i 484 . . . . . . . . . . . . . . . 16 |- ((Lim dom g /\ z = U.ran g) <-> ((-. g = (/) /\ Lim dom g) /\ z = U.ran g))
21 anass 441 . . . . . . . . . . . . . . . 16 |- (((-. g = (/) /\ Lim dom g) /\ z = U.ran g) <-> (-. g = (/) /\ (Lim dom g /\ z = U.ran g)))
2220, 21bitri 171 . . . . . . . . . . . . . . 15 |- ((Lim dom g /\ z = U.ran g) <-> (-. g = (/) /\ (Lim dom g /\ z = U.ran g)))
2310, 22orbi12i 255 . . . . . . . . . . . . . 14 |- (((-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g)) <-> ((-. g = (/) /\ (-. Lim dom g /\ z = (F` (g` U.dom g)))) \/ (-. g = (/) /\ (Lim dom g /\ z = U.ran g))))
246, 23bitr4i 174 . . . . . . . . . . . . 13 |- ((-. g = (/) /\ ((-. Lim dom g /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))) <-> ((-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g)))
253, 5, 243bitri 175 . . . . . . . . . . . 12 |- ((-. g = (/) /\ z = if(Lim dom g, U.ran g, (F` (g` U.dom g)))) <-> ((-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g)))
2625orbi2i 253 . . . . . . . . . . 11 |- (((g = (/) /\ z = A) \/ (-. g = (/) /\ z = if(Lim dom g, U.ran g, (F` (g` U.dom g))))) <-> ((g = (/) /\ z = A) \/ ((-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))))
27 eqif 2431 . . . . . . . . . . 11 |- (z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g)))) <-> ((g = (/) /\ z = A) \/ (-. g = (/) /\ z = if(Lim dom g, U.ran g, (F` (g` U.dom g))))))
28 3orass 784 . . . . . . . . . . 11 |- (((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g)) <-> ((g = (/) /\ z = A) \/ ((-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))))
2926, 27, 283bitr4i 181 . . . . . . . . . 10 |- (z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g)))) <-> ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g)))
3029opabbii 2745 . . . . . . . . 9 |- {<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))} = {<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}
3130fveq1i 3836 . . . . . . . 8 |- ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y)) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y))
3231eqeq2i 1528 . . . . . . 7 |- ((f` y) = ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y)) <-> (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y)))
3332ralbii 1713 . . . . . 6 |- (A.y e. x (f` y) = ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y)) <-> A.y e. x (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y)))
3433anbi2i 483 . . . . 5 |- ((f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y))) <-> (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y))))
3534rexbii 1714 . . . 4 |- (E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y))) <-> E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y))))
3635abbii 1618 . . 3 |- {f | E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y)))} = {f | E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y)))}
3736unieqi 2577 . 2 |- U.{f | E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | z = if(g = (/), A, if(Lim dom g, U.ran g, (F` (g` U.dom g))))}` (f |` y)))} = U.{f | E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y)))}
381, 37eqtri 1538 1 |- rec(F, A) = U.{f | E.x e. On (f Fn x /\ A.y e. x (f` y) = ({<.g, z>. | ((g = (/) /\ z = A) \/ (-. (g = (/) \/ Lim dom g) /\ z = (F` (g` U.dom g))) \/ (Lim dom g /\ z = U.ran g))}` (f |` y)))}
Colors of variables: wff set class
Syntax hints:  -. wn 2   \/ wo 220   /\ wa 221   \/ w3o 780   = wceq 992  {cab 1505  A.wral 1691  E.wrex 1692  (/)c0 2332  ifcif 2415  U.cuni 2569  {copab 2740  Oncon0 2975  Lim wlim 2976  dom cdm 3251  ran crn 3252   |` cres 3253   Fn wfn 3258  ` cfv 3263  reccrdg 4232
This theorem is referenced by:  rdgval 4241
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 998  ax-gen 999  ax-8 1000  ax-10 1002  ax-11 1003  ax-12 1004  ax-13 1005  ax-14 1006  ax-17 1007  ax-4 1009  ax-5o 1011  ax-6o 1014  ax-9o 1159  ax-10o 1177  ax-16 1247  ax-11o 1255  ax-ext 1500  ax-sep 2777  ax-pow 2818  ax-pr 2855
This theorem depends on definitions:  df-bi 145  df-or 222  df-an 223  df-3or 782  df-3an 783  df-ex 1017  df-sb 1209  df-eu 1421  df-mo 1422  df-clab 1506  df-cleq 1511  df-clel 1514  df-ne 1630  df-ral 1695  df-rex 1696  df-v 1858  df-dif 2101  df-un 2102  df-in 2103  df-ss 2105  df-nul 2333  df-if 2416  df-pw 2459  df-sn 2470  df-pr 2471  df-op 2474  df-uni 2570  df-br 2693  df-opab 2741  df-tr 2755  df-po 2918  df-so 2929  df-fr 2947  df-we 2962  df-ord 2978  df-lim 2980  df-cnv 3267  df-dm 3269  df-rn 3270  df-res 3271  df-ima 3272  df-fv 3279  df-rdg 4233
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