"CODE" 34424;
  "PROCEDURE" SOLTRI(SUB, DIAG, SUPER, N, B);
  "VALUE" N; "INTEGER" N; "ARRAY" SUB, DIAG, SUPER, B;
  "BEGIN" "INTEGER" I;
     "REAL" R;
     R:= B[1]:= B[1] / DIAG[1];
     "FOR" I:= 2 "STEP" 1 "UNTIL" N "DO"
     R:= B[I]:= (B[I] - SUB[I - 1] * R) / DIAG[I];
     "FOR" I:= N - 1 "STEP" -1 "UNTIL" 1 "DO"
     R:= B[I] := B[I] - SUPER[I] * R
  "END" SOLTRI;
        "EOP"