let S be OrderSortedSign; for X being V5() ManySortedSet of S
for o being OperSymbol of S
for x being Element of Args o,(ParsedTermsOSA X)
for t being Element of TS (DTConOSA X) st t = (Den o,(ParsedTermsOSA X)) . x holds
LeastSort t = the_result_sort_of o
let X be V5() ManySortedSet of S; for o being OperSymbol of S
for x being Element of Args o,(ParsedTermsOSA X)
for t being Element of TS (DTConOSA X) st t = (Den o,(ParsedTermsOSA X)) . x holds
LeastSort t = the_result_sort_of o
let o be OperSymbol of S; for x being Element of Args o,(ParsedTermsOSA X)
for t being Element of TS (DTConOSA X) st t = (Den o,(ParsedTermsOSA X)) . x holds
LeastSort t = the_result_sort_of o
let x be Element of Args o,(ParsedTermsOSA X); for t being Element of TS (DTConOSA X) st t = (Den o,(ParsedTermsOSA X)) . x holds
LeastSort t = the_result_sort_of o
reconsider x1 = x as FinSequence of TS (DTConOSA X) by Th13;
set PTA = ParsedTermsOSA X;
let t be Element of TS (DTConOSA X); ( t = (Den o,(ParsedTermsOSA X)) . x implies LeastSort t = the_result_sort_of o )
assume A1:
t = (Den o,(ParsedTermsOSA X)) . x
; LeastSort t = the_result_sort_of o
OSSym o,X ==> roots x
by Th13;
then consider o1 being OperSymbol of S such that
A2:
OSSym o,X = [o1,the carrier of S]
and
x1 in Args o1,(ParsedTermsOSA X)
and
A3:
(OSSym o,X) -tree x1 = (Den o1,(ParsedTermsOSA X)) . x1
and
A4:
for s1 being Element of S holds
( (OSSym o,X) -tree x1 in the Sorts of (ParsedTermsOSA X) . s1 iff the_result_sort_of o1 <= s1 )
by Th12;
A5:
o = o1
by A2, ZFMISC_1:33;
then
t in the Sorts of (ParsedTermsOSA X) . (the_result_sort_of o)
by A1, A3, A4;
hence
LeastSort t = the_result_sort_of o
by A1, A3, A4, A5, Def12; verum