let i be Nat; :: thesis: for D, D', E being non empty set
for d being Element of D
for F being Function of [:D,D':],E
for z being Element of i -tuples_on D' holds F [;] d,z is Element of i -tuples_on E
let D, D', E be non empty set ; :: thesis: for d being Element of D
for F being Function of [:D,D':],E
for z being Element of i -tuples_on D' holds F [;] d,z is Element of i -tuples_on E
let d be Element of D; :: thesis: for F being Function of [:D,D':],E
for z being Element of i -tuples_on D' holds F [;] d,z is Element of i -tuples_on E
let F be Function of [:D,D':],E; :: thesis: for z being Element of i -tuples_on D' holds F [;] d,z is Element of i -tuples_on E
let z be Element of i -tuples_on D'; :: thesis: F [;] d,z is Element of i -tuples_on E
reconsider r = F [;] d,z as FinSequence of E by Th91;
len z = i by FINSEQ_1:def 18;
then len r = i by Th92;
hence F [;] d,z is Element of i -tuples_on E by Th110; :: thesis: verum