let I be set ; for S being non empty non void ManySortedSign
for A being MSAlgebra-Family of I,S
for o being OperSymbol of S
for x being Element of Args (o,(product A)) holds (Den (o,(product A))) . x in product (Carrier (A,(the_result_sort_of o)))
let S be non empty non void ManySortedSign ; for A being MSAlgebra-Family of I,S
for o being OperSymbol of S
for x being Element of Args (o,(product A)) holds (Den (o,(product A))) . x in product (Carrier (A,(the_result_sort_of o)))
let A be MSAlgebra-Family of I,S; for o being OperSymbol of S
for x being Element of Args (o,(product A)) holds (Den (o,(product A))) . x in product (Carrier (A,(the_result_sort_of o)))
let o be OperSymbol of S; for x being Element of Args (o,(product A)) holds (Den (o,(product A))) . x in product (Carrier (A,(the_result_sort_of o)))
let x be Element of Args (o,(product A)); (Den (o,(product A))) . x in product (Carrier (A,(the_result_sort_of o)))
Result (o,(product A)) =
(SORTS A) . (the_result_sort_of o)
by PRALG_2:3
.=
product (Carrier (A,(the_result_sort_of o)))
by PRALG_2:def 10
;
hence
(Den (o,(product A))) . x in product (Carrier (A,(the_result_sort_of o)))
; verum