% first line
:- use_module(library(clpfd)).

ceiled_square_root(0, 0).
ceiled_square_root(N0, Root) :-
        N1 #= N0 - 1,
        Max in 0..N1,
        R0^2 #= Max,
        Root #= Root0 + 1,
        fd_sup(R0, Root0).
% 1
% 2
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% 4 almost empty lines; next line is: line 15
%?- time(ceiled_square_root(2^10000, R)).