ISINF
if (ISINF(iy, ly)) { /* cacos(x + i inf) = pi/2 - i inf */
} else if (ISINF(ix, lx)) {
if (ISINF(ix, lx))
if (ISINF(ix, lx)) { /* x is INF */
if (ISINF(iy, ly)) {
if (ISINF(ix, lx)) { /* x is INF */
if (ISINF(iy, ly))
if (ISINF(iy, ly)) { /* casin(x + i inf) = 0 + i inf */
if (ISINF(ix, lx)) {
if ((iy | ly) == 0 || (ISINF(iy, ly)))
if (ISINF(iy, ly)) {
} else if (ISINF(ix, lx)) { /* x is +-inf */
if (ISINF(ix, lx))
else if (ISINF(iy, ly))
if (ISINF(iy, ly)) {
} else if (ISINF(ix, lx)) {
if (ISINF(iy, ly))
else if (ISINF(ix, lx)) {
if (ISINF(ix, lx))
else if (ISINF(iy, ly))