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Theorem algrf 12742
Description: An algorithm is a step function  F : S --> S on a state space  S. An algorithm acts on an initial state  A  e.  S by iteratively applying  F to give  A,  ( F `  A ),  ( F `  ( F `  A )
) and so on. An algorithm is said to halt if a fixed point of  F is reached after a finite number of iterations.

The algorithm iterator  R : NN0 --> S "runs" the algorithm  F so that  ( R `  k ) is the state after  k iterations of  F on the initial state  A.

Domain and codomain of the algorithm iterator  R. (Contributed by Paul Chapman, 31-Mar-2011.) (Revised by Mario Carneiro, 28-May-2014.)

Hypotheses
Ref Expression
algrf.1  |-  Z  =  ( ZZ>= `  M )
algrf.2  |-  R  =  seq M ( ( F  o.  1st ) ,  ( Z  X.  { A } ) )
algrf.3  |-  ( ph  ->  M  e.  ZZ )
algrf.4  |-  ( ph  ->  A  e.  S )
algrf.5  |-  ( ph  ->  F : S --> S )
Assertion
Ref Expression
algrf  |-  ( ph  ->  R : Z --> S )

Proof of Theorem algrf
Dummy variables  x  y are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 algrf.1 . . 3  |-  Z  =  ( ZZ>= `  M )
2 algrf.3 . . 3  |-  ( ph  ->  M  e.  ZZ )
3 algrf.4 . . . . 5  |-  ( ph  ->  A  e.  S )
4 fvconst2g 5898 . . . . 5  |-  ( ( A  e.  S  /\  x  e.  Z )  ->  ( ( Z  X.  { A } ) `  x )  =  A )
53, 4sylan 283 . . . 4  |-  ( (
ph  /\  x  e.  Z )  ->  (
( Z  X.  { A } ) `  x
)  =  A )
63adantr 276 . . . 4  |-  ( (
ph  /\  x  e.  Z )  ->  A  e.  S )
75, 6eqeltrd 2309 . . 3  |-  ( (
ph  /\  x  e.  Z )  ->  (
( Z  X.  { A } ) `  x
)  e.  S )
8 vex 2816 . . . . 5  |-  x  e. 
_V
9 vex 2816 . . . . 5  |-  y  e. 
_V
108, 9algrflem 6425 . . . 4  |-  ( x ( F  o.  1st ) y )  =  ( F `  x
)
11 algrf.5 . . . . 5  |-  ( ph  ->  F : S --> S )
12 simpl 109 . . . . 5  |-  ( ( x  e.  S  /\  y  e.  S )  ->  x  e.  S )
13 ffvelcdm 5810 . . . . 5  |-  ( ( F : S --> S  /\  x  e.  S )  ->  ( F `  x
)  e.  S )
1411, 12, 13syl2an 289 . . . 4  |-  ( (
ph  /\  ( x  e.  S  /\  y  e.  S ) )  -> 
( F `  x
)  e.  S )
1510, 14eqeltrid 2319 . . 3  |-  ( (
ph  /\  ( x  e.  S  /\  y  e.  S ) )  -> 
( x ( F  o.  1st ) y )  e.  S )
161, 2, 7, 15seqf 10826 . 2  |-  ( ph  ->  seq M ( ( F  o.  1st ) ,  ( Z  X.  { A } ) ) : Z --> S )
17 algrf.2 . . 3  |-  R  =  seq M ( ( F  o.  1st ) ,  ( Z  X.  { A } ) )
1817feq1i 5501 . 2  |-  ( R : Z --> S  <->  seq M ( ( F  o.  1st ) ,  ( Z  X.  { A } ) ) : Z --> S )
1916, 18sylibr 134 1  |-  ( ph  ->  R : Z --> S )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    = wceq 1398    e. wcel 2203   {csn 3689    X. cxp 4747    o. ccom 4753   -->wf 5348   ` cfv 5352  (class class class)co 6050   1stc1st 6332   ZZcz 9577   ZZ>=cuz 9853    seqcseq 10809
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2205  ax-14 2206  ax-ext 2214  ax-coll 4225  ax-sep 4228  ax-nul 4236  ax-pow 4287  ax-pr 4322  ax-un 4554  ax-setind 4659  ax-iinf 4710  ax-cnex 8218  ax-resscn 8219  ax-1cn 8220  ax-1re 8221  ax-icn 8222  ax-addcl 8223  ax-addrcl 8224  ax-mulcl 8225  ax-addcom 8227  ax-addass 8229  ax-distr 8231  ax-i2m1 8232  ax-0lt1 8233  ax-0id 8235  ax-rnegex 8236  ax-cnre 8238  ax-pre-ltirr 8239  ax-pre-ltwlin 8240  ax-pre-lttrn 8241  ax-pre-ltadd 8243
This theorem depends on definitions:  df-bi 117  df-3or 1006  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1812  df-eu 2083  df-mo 2084  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-ne 2413  df-nel 2508  df-ral 2525  df-rex 2526  df-reu 2527  df-rab 2529  df-v 2815  df-sbc 3043  df-csb 3139  df-dif 3213  df-un 3215  df-in 3217  df-ss 3224  df-nul 3509  df-pw 3671  df-sn 3695  df-pr 3696  df-op 3698  df-uni 3915  df-int 3950  df-iun 3993  df-br 4110  df-opab 4172  df-mpt 4173  df-tr 4209  df-id 4414  df-iord 4487  df-on 4489  df-ilim 4490  df-suc 4492  df-iom 4713  df-xp 4755  df-rel 4756  df-cnv 4757  df-co 4758  df-dm 4759  df-rn 4760  df-res 4761  df-ima 4762  df-iota 5312  df-fun 5354  df-fn 5355  df-f 5356  df-f1 5357  df-fo 5358  df-f1o 5359  df-fv 5360  df-riota 6003  df-ov 6053  df-oprab 6054  df-mpo 6055  df-1st 6334  df-2nd 6335  df-recs 6536  df-frec 6622  df-pnf 8310  df-mnf 8311  df-xr 8312  df-ltxr 8313  df-le 8314  df-sub 8446  df-neg 8447  df-inn 9238  df-n0 9497  df-z 9578  df-uz 9854  df-seqfrec 10810
This theorem is referenced by:  algrp1  12743  alginv  12744  algcvg  12745  algcvga  12748  algfx  12749  eucalgcvga  12755  eucalg  12756
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