let D, D', E be non empty set ; for d being Element of D
for d1', d2' being Element of D'
for F being Function of [:D,D':],E
for p being FinSequence of D' st p = <*d1',d2'*> holds
F [;] d,p = <*(F . d,d1'),(F . d,d2')*>
let d be Element of D; for d1', d2' being Element of D'
for F being Function of [:D,D':],E
for p being FinSequence of D' st p = <*d1',d2'*> holds
F [;] d,p = <*(F . d,d1'),(F . d,d2')*>
let d1', d2' be Element of D'; for F being Function of [:D,D':],E
for p being FinSequence of D' st p = <*d1',d2'*> holds
F [;] d,p = <*(F . d,d1'),(F . d,d2')*>
let F be Function of [:D,D':],E; for p being FinSequence of D' st p = <*d1',d2'*> holds
F [;] d,p = <*(F . d,d1'),(F . d,d2')*>
let p be FinSequence of D'; ( p = <*d1',d2'*> implies F [;] d,p = <*(F . d,d1'),(F . d,d2')*> )
assume A1:
p = <*d1',d2'*>
; F [;] d,p = <*(F . d,d1'),(F . d,d2')*>
A2:
p . 2 = d2'
by A1, FINSEQ_1:61;
reconsider r = F [;] d,p as FinSequence of E by Th91;
len p = 2
by A1, FINSEQ_1:61;
then A3:
len r = 2
by Th92;
then
2 in Seg (len r)
;
then
2 in dom r
by FINSEQ_1:def 3;
then A4:
r . 2 = F . d,d2'
by A2, FUNCOP_1:42;
1 in Seg (len r)
by A3;
then A5:
1 in dom r
by FINSEQ_1:def 3;
p . 1 = d1'
by A1, FINSEQ_1:61;
then
r . 1 = F . d,d1'
by A5, FUNCOP_1:42;
hence
F [;] d,p = <*(F . d,d1'),(F . d,d2')*>
by A3, A4, FINSEQ_1:61; verum