D.15.25.7 Sfunction

Usage:

Sfunction(z,k); z poly, k int

Assume:

z is a polynomial and k is an integer

Return:

poly

Theory:

Returns the S-function in the form of (1+X), where X is a taylor series expansion of the sinh function upto k terms.

LIB "tropicalEllipticCovers.lib";
ring R=0,(x,y),dp;
Sfunction(x,3);