let D, D9, E be non empty set ; :: thesis: for d1, d2, d3 being Element of D
for d9 being Element of D9
for F being Function of [:D,D9:],E
for p being FinSequence of D st p = <*d1,d2,d3*> holds
F [:] p,d9 = <*(F . d1,d9),(F . d2,d9),(F . d3,d9)*>

let d1, d2, d3 be Element of D; :: thesis: for d9 being Element of D9
for F being Function of [:D,D9:],E
for p being FinSequence of D st p = <*d1,d2,d3*> holds
F [:] p,d9 = <*(F . d1,d9),(F . d2,d9),(F . d3,d9)*>

let d9 be Element of D9; :: thesis: for F being Function of [:D,D9:],E
for p being FinSequence of D st p = <*d1,d2,d3*> holds
F [:] p,d9 = <*(F . d1,d9),(F . d2,d9),(F . d3,d9)*>

let F be Function of [:D,D9:],E; :: thesis: for p being FinSequence of D st p = <*d1,d2,d3*> holds
F [:] p,d9 = <*(F . d1,d9),(F . d2,d9),(F . d3,d9)*>

let p be FinSequence of D; :: thesis: ( p = <*d1,d2,d3*> implies F [:] p,d9 = <*(F . d1,d9),(F . d2,d9),(F . d3,d9)*> )
assume A1: p = <*d1,d2,d3*> ; :: thesis: F [:] p,d9 = <*(F . d1,d9),(F . d2,d9),(F . d3,d9)*>
A2: p . 2 = d2 by A1, FINSEQ_1:62;
reconsider r = F [:] p,d9 as FinSequence of E by Th97;
len p = 3 by A1, FINSEQ_1:62;
then A3: len r = 3 by Th98;
then 2 in Seg (len r) ;
then 2 in dom r by FINSEQ_1:def 3;
then A4: r . 2 = F . d2,d9 by A2, FUNCOP_1:35;
A5: p . 3 = d3 by A1, FINSEQ_1:62;
A6: p . 1 = d1 by A1, FINSEQ_1:62;
3 in Seg (len r) by A3;
then 3 in dom r by FINSEQ_1:def 3;
then A7: r . 3 = F . d3,d9 by A5, FUNCOP_1:35;
1 in Seg (len r) by A3;
then 1 in dom r by FINSEQ_1:def 3;
then r . 1 = F . d1,d9 by A6, FUNCOP_1:35;
hence F [:] p,d9 = <*(F . d1,d9),(F . d2,d9),(F . d3,d9)*> by A3, A4, A7, FINSEQ_1:62; :: thesis: verum