/*	computes a^b.	uses log and exp*/#include	<errno.h>int errno;double log(), exp();doublepow(arg1,arg2)double arg1, arg2;{	double temp;	long l;	if(arg1 <= 0.) {		if(arg1 == 0.) {			if(arg2 <= 0.)				goto domain;			return(0.);		}		l = arg2;		if(l != arg2)			goto domain;		temp = exp(arg2 * log(-arg1));		if(l & 1)			temp = -temp;		return(temp);	}	return(exp(arg2 * log(arg1)));domain:	errno = EDOM;	return(0.);}