let S be non empty non void ManySortedSign ; for o being OperSymbol of S
for X being V5() ManySortedSet of the carrier of S
for p being Element of Args (o,(Free (S,X))) st the_arity_of o = {} holds
height (o -term p) = 0
let o be OperSymbol of S; for X being V5() ManySortedSet of the carrier of S
for p being Element of Args (o,(Free (S,X))) st the_arity_of o = {} holds
height (o -term p) = 0
let X be V5() ManySortedSet of the carrier of S; for p being Element of Args (o,(Free (S,X))) st the_arity_of o = {} holds
height (o -term p) = 0
let p be Element of Args (o,(Free (S,X))); ( the_arity_of o = {} implies height (o -term p) = 0 )
assume
the_arity_of o = {}
; height (o -term p) = 0
then
dom p = dom {}
by MSUALG_3:6;
then
p = {}
;
then
o -term p = root-tree [o, the carrier of S]
by TREES_4:20;
hence
height (o -term p) = 0
by FUNCOP_1:13, TREES_1:42; verum