USUB              603 src/bignum.c                   USUB(br->values[i], c, 0, 0);
USUB              607 src/bignum.c               USUB(br->values[i], c, 0, y);
USUB              612 src/bignum.c               USUB(br->values[i], c, x, 0);
USUB              617 src/bignum.c           USUB(br->values[i], c, x, y);
USUB              674 src/bignum.c               USUB(br->values[i], c, bx->values[i], yabs);
USUB              132 src/gauche/arith.h #ifndef USUB
USUB              197 src/test-arith.c     TEST5(x_, y_, c_, rexp, cexp, "%u", "-", USUB)