let IAlph, OAlph be non empty set ; :: thesis: for w1, w2 being FinSequence of IAlph
for tfsm being non empty Mealy-FSM of IAlph,OAlph
for q1t, q2t being State of tfsm st q1t,w1 -leads_to q2t holds
q1t,(w1 ^ w2) -response = (q1t,w1 -response ) ^ (q2t,w2 -response )

let w1, w2 be FinSequence of IAlph; :: thesis: for tfsm being non empty Mealy-FSM of IAlph,OAlph
for q1t, q2t being State of tfsm st q1t,w1 -leads_to q2t holds
q1t,(w1 ^ w2) -response = (q1t,w1 -response ) ^ (q2t,w2 -response )

let tfsm be non empty Mealy-FSM of IAlph,OAlph; :: thesis: for q1t, q2t being State of tfsm st q1t,w1 -leads_to q2t holds
q1t,(w1 ^ w2) -response = (q1t,w1 -response ) ^ (q2t,w2 -response )

let q1t, q2t be State of tfsm; :: thesis: ( q1t,w1 -leads_to q2t implies q1t,(w1 ^ w2) -response = (q1t,w1 -response ) ^ (q2t,w2 -response ) )
assume A1: q1t,w1 -leads_to q2t ; :: thesis: q1t,(w1 ^ w2) -response = (q1t,w1 -response ) ^ (q2t,w2 -response )
set q1w1 = q1t,w1 -response ;
set q2w2 = q2t,w2 -response ;
set q1w1w2 = q1t,(w1 ^ w2) -response ;
set Dq1w1w2a = Del (q1t,w1 -admissible ),((len w1) + 1);
set OF = the OFun of tfsm;
A2: len (q1t,(w1 ^ w2) -response ) = len (w1 ^ w2) by Def6
.= (len w1) + (len w2) by FINSEQ_1:35
.= (len (q1t,w1 -response )) + (len w2) by Def6
.= (len (q1t,w1 -response )) + (len (q2t,w2 -response )) by Def6
.= len ((q1t,w1 -response ) ^ (q2t,w2 -response )) by FINSEQ_1:35 ;
now
let k be Nat; :: thesis: ( 1 <= k & k <= len (q1t,(w1 ^ w2) -response ) implies (q1t,(w1 ^ w2) -response ) . b1 = ((q1t,w1 -response ) ^ (q2t,w2 -response )) . b1 )
assume A3: ( 1 <= k & k <= len (q1t,(w1 ^ w2) -response ) ) ; :: thesis: (q1t,(w1 ^ w2) -response ) . b1 = ((q1t,w1 -response ) ^ (q2t,w2 -response )) . b1
A4: k in NAT by ORDINAL1:def 13;
A5: len (q1t,w1 -admissible ) = (len w1) + 1 by Def2;
dom (q1t,w1 -admissible ) = Seg (len (q1t,w1 -admissible )) by FINSEQ_1:def 3;
then dom (q1t,w1 -admissible ) = Seg ((len w1) + 1) by Def2;
then (len w1) + 1 in dom (q1t,w1 -admissible ) by FINSEQ_1:5;
then consider m being Nat such that
A6: ( len (q1t,w1 -admissible ) = m + 1 & len (Del (q1t,w1 -admissible ),((len w1) + 1)) = m ) by FINSEQ_3:113;
A7: m + 1 = (len w1) + 1 by A6, Def2;
A8: len (q1t,w1 -response ) = len w1 by Def6;
per cases ( ( 1 <= k & k <= len (q1t,w1 -response ) ) or ( (len (q1t,w1 -response )) + 1 <= k & k <= len (q1t,(w1 ^ w2) -response ) ) ) by A3, NAT_1:13;
suppose A9: ( 1 <= k & k <= len (q1t,w1 -response ) ) ; :: thesis: (q1t,(w1 ^ w2) -response ) . b1 = ((q1t,w1 -response ) ^ (q2t,w2 -response )) . b1
then A10: ( 1 <= k & k <= len w1 ) by Def6;
then A11: k in dom w1 by FINSEQ_3:27;
( 1 <= k & k <= len (w1 ^ w2) ) by A3, Def6;
then A12: k in dom (w1 ^ w2) by FINSEQ_3:27;
A13: k in dom (q1t,w1 -response ) by A9, FINSEQ_3:27;
A14: ( 1 <= k & k < (len w1) + 1 ) by A10, NAT_1:13;
A15: k in dom (Del (q1t,w1 -admissible ),((len w1) + 1)) by A6, A7, A10, FINSEQ_3:27;
thus (q1t,(w1 ^ w2) -response ) . k = the OFun of tfsm . [((q1t,(w1 ^ w2) -admissible ) . k),((w1 ^ w2) . k)] by A12, Def6
.= the OFun of tfsm . [(((Del (q1t,w1 -admissible ),((len w1) + 1)) ^ (q2t,w2 -admissible )) . k),((w1 ^ w2) . k)] by A1, Th23
.= the OFun of tfsm . [((Del (q1t,w1 -admissible ),((len w1) + 1)) . k),((w1 ^ w2) . k)] by A15, FINSEQ_1:def 7
.= the OFun of tfsm . [((Del (q1t,w1 -admissible ),((len w1) + 1)) . k),(w1 . k)] by A11, FINSEQ_1:def 7
.= the OFun of tfsm . [((q1t,w1 -admissible ) . k),(w1 . k)] by A4, A5, A14, FINSEQ_3:119
.= (q1t,w1 -response ) . k by A11, Def6
.= ((q1t,w1 -response ) ^ (q2t,w2 -response )) . k by A13, FINSEQ_1:def 7 ; :: thesis: verum
end;
suppose A16: ( (len (q1t,w1 -response )) + 1 <= k & k <= len (q1t,(w1 ^ w2) -response ) ) ; :: thesis: (q1t,(w1 ^ w2) -response ) . b1 = ((q1t,w1 -response ) ^ (q2t,w2 -response )) . b1
( 1 <= k & k <= len (w1 ^ w2) ) by A3, Def6;
then A17: k in dom (w1 ^ w2) by FINSEQ_3:27;
A18: len (q1t,(w1 ^ w2) -response ) = len (w1 ^ w2) by Def6
.= (len w1) + (len w2) by FINSEQ_1:35
.= (len (q1t,w1 -response )) + (len w2) by Def6
.= (len (q1t,w1 -response )) + (len (q2t,w2 -response )) by Def6 ;
then A19: k <= (len (Del (q1t,w1 -admissible ),((len w1) + 1))) + (len w2) by A6, A7, A8, A16, Def6;
len w2 <= (len w2) + 1 by NAT_1:11;
then (len (Del (q1t,w1 -admissible ),((len w1) + 1))) + (len w2) <= (len (Del (q1t,w1 -admissible ),((len w1) + 1))) + ((len w2) + 1) by XREAL_1:8;
then k <= (len (Del (q1t,w1 -admissible ),((len w1) + 1))) + ((len w2) + 1) by A19, XXREAL_0:2;
then A20: ( (len (Del (q1t,w1 -admissible ),((len w1) + 1))) + 1 <= k & k <= (len (Del (q1t,w1 -admissible ),((len w1) + 1))) + (len (q2t,w2 -admissible )) ) by A6, A7, A16, Def2, Def6;
A21: len (q1t,(w1 ^ w2) -response ) = len (w1 ^ w2) by Def6
.= (len w1) + (len w2) by FINSEQ_1:35 ;
then A22: ( (len w1) + 1 <= k & k <= (len w1) + (len w2) ) by A16, Def6;
A23: (q1t,(w1 ^ w2) -response ) . k = the OFun of tfsm . [((q1t,(w1 ^ w2) -admissible ) . k),((w1 ^ w2) . k)] by A17, Def6
.= the OFun of tfsm . [(((Del (q1t,w1 -admissible ),((len w1) + 1)) ^ (q2t,w2 -admissible )) . k),((w1 ^ w2) . k)] by A1, Th23
.= the OFun of tfsm . [((q2t,w2 -admissible ) . (k - (len (Del (q1t,w1 -admissible ),((len w1) + 1))))),((w1 ^ w2) . k)] by A20, FINSEQ_1:36
.= the OFun of tfsm . [((q2t,w2 -admissible ) . (k - (len w1))),(w2 . (k - (len w1)))] by A6, A7, A22, FINSEQ_1:36 ;
A24: ((len (q1t,w1 -response )) + 1) - (len (q1t,w1 -response )) <= k - (len (q1t,w1 -response )) by A16, XREAL_1:11;
then reconsider p = k - (len (q1t,w1 -response )) as Element of NAT by INT_1:16;
k <= (len (q1t,w1 -response )) + (len w2) by A16, A21, Def6;
then k - (len (q1t,w1 -response )) <= ((len (q1t,w1 -response )) + (len w2)) - (len (q1t,w1 -response )) by XREAL_1:11;
then A25: p in dom w2 by A24, FINSEQ_3:27;
((q1t,w1 -response ) ^ (q2t,w2 -response )) . k = (q2t,w2 -response ) . p by A16, A18, FINSEQ_1:36
.= the OFun of tfsm . [((q2t,w2 -admissible ) . p),(w2 . p)] by A25, Def6
.= the OFun of tfsm . [((q2t,w2 -admissible ) . (k - (len w1))),(w2 . (k - (len (q1t,w1 -response ))))] by Def6
.= the OFun of tfsm . [((q2t,w2 -admissible ) . (k - (len w1))),(w2 . (k - (len w1)))] by Def6 ;
hence (q1t,(w1 ^ w2) -response ) . k = ((q1t,w1 -response ) ^ (q2t,w2 -response )) . k by A23; :: thesis: verum
end;
end;
end;
hence q1t,(w1 ^ w2) -response = (q1t,w1 -response ) ^ (q2t,w2 -response ) by A2, FINSEQ_1:18; :: thesis: verum