check(a,b)=my(c=abs(a-b)); if(!c,-oo, ceil(log(c)/log(10)));
f(s,x)=check(zetahurwitz(s,x)+zetahurwitz(s,x+1/2), 2^s*zetahurwitz(s,2*x));
f(Pi,Pi)
f(Pi,Pi+I*log(2))
check(zetahurwitz(Pi,1),zeta(Pi))
s = Pi+I*log(2);
check(zetahurwitz(s,1), zeta(s))
check(zetahurwitz(s,3), zeta(s)-1-1/2^s)
check((zetahurwitz(s,1/4)-zetahurwitz(s,3/4))/4^s, lfun(-4,s))
check(zetahurwitz(-3.4,1), zeta(-3.4))
check(zetahurwitz(2.1,1,2), zeta''(2.1))
zetahurwitz(2, 21)
zetahurwitz(2, I, 18)
zetahurwitz(7+O(7^5),1)
zetahurwitz(7+O(7^5),2)
zetahurwitz(3+O(2^5),1/2)
zetahurwitz(3+O(2^5),1/4)
zetahurwitz(3,2+O(5^5))
zetahurwitz(3+O(7^12),0,-2)
zetahurwitz(7+O(17^120),0,-6) == psi(O(17^120),6)/-6!
zetahurwitz(-2.3,Pi+I*log(2))
zetahurwitz(-1+x^2,1)
zetahurwitz(1+x + O(x^7),2)
zetahurwitz(x,1+x)
zetahurwitz(x,2)
zetahurwitz(x,2,1)
zetahurwitz(4,2^20)
zetahurwitz(4,2^100)
zetahurwitz(4,2.^128)
zetahurwitz(-1,1)
zetahurwitz(-2,I)
zetahurwitz(1/2+100000*I,1/2)
zetahurwitz(2,20*I)

\\ ERRORS
zetahurwitz(1,Pi)
zetahurwitz(1+O(x),1)
zetahurwitz(O(2)+x,1)
zetahurwitz(y+x,1)
zetahurwitz([],[])
