consider A being non empty set ;
consider a being Element of A;
reconsider w = (<*> A) .--> a as Element of PFuncs ((A *),A) by MARGREL1:55;
set U0 = UAStr(# A,<*w*> #);
A1: ( the charact of UAStr(# A,<*w*> #) is quasi_total & the charact of UAStr(# A,<*w*> #) is homogeneous ) by MARGREL1:56;
the charact of UAStr(# A,<*w*> #) is non-empty by MARGREL1:56;
then reconsider U0 = UAStr(# A,<*w*> #) as Universal_Algebra by A1, UNIALG_1:def 7, UNIALG_1:def 8, UNIALG_1:def 9;
take U0 ; :: thesis: ( U0 is with_const_op & U0 is strict )
( dom <*w*> = {1} & 1 in {1} ) by FINSEQ_1:4, FINSEQ_1:55, TARSKI:def 1;
then reconsider o = the charact of U0 . 1 as operation of U0 by FUNCT_1:def 5;
o = w by FINSEQ_1:57;
then A2: dom o = {(<*> A)} by FUNCOP_1:19;

A3: now

let x be FinSequence; :: thesis: ( x in dom o implies len x = 0 )
assume x in dom o ; :: thesis: len x = 0
then x = <*> A by A2, TARSKI:def 1;
hence len x = 0 ; :: thesis: verum

end;

<*> A in {(<*> A)} by TARSKI:def 1;
then arity o = 0 by A2, A3, MARGREL1:def 26;
hence ( U0 is with_const_op & U0 is strict ) by Def12; :: thesis: verum