"CODE" 31052;
"PROCEDURE" CHSPOL(N,A);
"VALUE" N; "INTEGER" N; "ARRAY" A;
"IF" N>1 "THEN"
"BEGIN"
    "INTEGER" K,L,TWOPOW;
    "FOR" K:=0 "STEP" 1 "UNTIL" N-2 "DO"
    "BEGIN"
        "FOR" L:=N-2 "STEP" -1 "UNTIL" K "DO"
        A[L]:=A[L]-A[L+2]; A[K+1]:=A[K+1]/2;
    "END";
    TWOPOW:=2;
    "FOR" K:=1 "STEP" 1 "UNTIL" N-2 "DO"
    "BEGIN"
        A[K]:=A[K]*TWOPOW; TWOPOW:=TWOPOW*2;
    "END";
    A[N-1]:=TWOPOW*A[N-1];
    A[N]:=TWOPOW*A[N];
"END" CHSPOL

        "EOP"