93 	dcomplex ans;  in catan()  local
112 			D_RE(ans) = pi_2;  in catan()
113 			D_IM(ans) = zero;  in catan()
115 			D_RE(ans) = x + x;  in catan()
117 				D_IM(ans) = zero;  in catan()
119 				D_IM(ans) = (fabs(y) - ay) / (fabs(y) - ay);  in catan()
124 			D_RE(ans) = pi_2;  in catan()
125 			D_IM(ans) = zero;  in catan()
127 			D_RE(ans) = (fabs(x) - ax) / (fabs(x) - ax);  in catan()
128 			D_IM(ans) = y;  in catan()
146 			D_IM(ans) = ay / ax;  in catan()
147 			D_RE(ans) = zero;  in catan()
149 			D_IM(ans) = half * log1p(two / (-t));  in catan()
150 			D_RE(ans) = pi_2;  in catan()
152 			D_IM(ans) = half * log1p((ay + ay) / t);  in catan()
153 			D_RE(ans) = zero;  in catan()
173 			D_RE(ans) = atan(ax);  in catan()
175 			D_RE(ans) = half * atan2(two, (one - ax) * (one +  in catan()
178 			D_IM(ans) = ay;  in catan()
186 			D_IM(ans) = t * (one - (t + t));  in catan()
201 		D_RE(ans) = pi_2;  in catan()
203 		D_IM(ans) = t * (one - (t + t));  in catan()
217 		D_RE(ans) = half * atan2(two, -ax);  in catan()
219 			D_IM(ans) = half * (ln2 - log(ax));  in catan()
222 			D_IM(ans) = 0.25 * log1p(t * t);  in catan()
237 		D_RE(ans) = pi_2;  in catan()
240 		D_IM(ans) = t * (one - (t + t));  in catan()
255 		D_RE(ans) = half * atan2(ax + ax, (one - ay) * (one + ay));  in catan()
257 			D_IM(ans) = half * log1p(two / (ay - one));  in catan()
259 			D_IM(ans) = half * log1p((ay + ay) / (one - ay));  in catan()
276 			D_RE(ans) = half * (atan2((ax + ax), (t * (one + ay) -  in catan()
280 			D_RE(ans) = half * atan2((ax + ax), ((one - ax) *  in catan()
283 			D_RE(ans) = half * atan2((ax + ax), ((one - ax * ax) -  in catan()
285 		D_IM(ans) = 0.25 * log1p((4.0 * ay) / (ax * ax + t * t));  in catan()
288 		D_RE(ans) = -D_RE(ans);  in catan()
290 		D_IM(ans) = -D_IM(ans);  in catan()
291 	return (ans);  in catan()