% prefix2infix(Inlist, OutList, OutExpr)
prefix_strom(Prefix, Strom) :- prefix2infix(Prefix, O, Strom),O = [].

prefix2infix([Number|T], T, Number) :- number(Number).

prefix2infix([Operator|T], OutSezn, OutExpr) :-
    ( (Operator = + ) ;(Operator = - ) ;(Operator = * ); (Operator = / ) ),

    (
    ((Operator = + ), OutExpr = OutExpr1 + OutExpr2);
    ((Operator = - ), OutExpr = OutExpr1 - OutExpr2);
    ((Operator = * ), OutExpr = OutExpr1 * OutExpr2);
    ((Operator = / ), OutExpr = OutExpr1 / OutExpr2)
    ),
    prefix2infix(T, OutSezn1, OutExpr1), % 1. operand
    prefix2infix(OutSezn1, OutSezn, OutExpr2) % 2. operand


.