symsum with multiple summation

To produce and solve following equation

I have written following equations

syms a d d1 k Nt PSI p Pi1 i

A=symsum( nchoosek(d,k) * PSI ( (1-PSI)^(d-k) ) nchoosek(k,a) (p^a)(1-p)^(k-a),d,0,Nt);

B=symsum ( (nchoosek(i,d1) * nchoosek(Nt-i,d-d1) (Pi1^d) (1-Pi1)^(Nt-d) ) * A ,i,0,Nt );

C=symsum( B, a,0,d);

M=symsum( C, d1,0,i )

where limits of summation for variables are as follows

Nt = 10 constant

d from 0 to Nt

d1 (d bar) from 0 to min(i,d), min gives error in symsum Error using symengine Input arguments must be convertible to floating-point numbers.

a from 0 to d

i from 0 to Nt

without using min() for limit of d1 script runs fine but can any one tell me that implementation i have done for multiple summation and their limits fine or limits or summation should follow any order also how can i add min(i,d) for d1 limit.