let S be non empty non void ManySortedSign ; for o being OperSymbol of S
for V being V16() ManySortedSet of the carrier of S
for x being Element of Args (o,(FreeMSA V)) holds (Den (o,(FreeMSA V))) . x = [o, the carrier of S] -tree x
let o be OperSymbol of S; for V being V16() ManySortedSet of the carrier of S
for x being Element of Args (o,(FreeMSA V)) holds (Den (o,(FreeMSA V))) . x = [o, the carrier of S] -tree x
let V be V16() ManySortedSet of the carrier of S; for x being Element of Args (o,(FreeMSA V)) holds (Den (o,(FreeMSA V))) . x = [o, the carrier of S] -tree x
let x be Element of Args (o,(FreeMSA V)); (Den (o,(FreeMSA V))) . x = [o, the carrier of S] -tree x
A1:
FreeMSA V = MSAlgebra(# (FreeSort V),(FreeOper V) #)
by MSAFREE:def 16;
reconsider p = x as ArgumentSeq of Sym (o,V) by Th2;
A2:
Sym (o,V) = [o, the carrier of S]
by MSAFREE:def 11;
( p is FinSequence of TS (DTConMSA V) & Sym (o,V) ==> roots p )
by MSATERM:21, MSATERM:def 1;
then
(DenOp (o,V)) . x = [o, the carrier of S] -tree x
by A2, MSAFREE:def 14;
hence
(Den (o,(FreeMSA V))) . x = [o, the carrier of S] -tree x
by A1, MSAFREE:def 15; verum