LIB "decomp.lib";
ring r0 = 0,x,dp;
is_composite(x4+5x2+6);    // biquadratic polynomial
==> 1
is_composite(2x2+x+1);     // prime degree
==>  The degree is prime.
==> 0
// -----------------------------------------------------------------------
// polynomial ring with several variables
ring R = 0,(x,y),dp;
// -----------------------------------------------------------------------
// single-variable multivariate polynomials
is_composite(2x+1);
==> 1
is_composite(2x2+x+1);
==> 1
// -----------------------------------------------------------------------
// prime characteristic
ring r7 = 7,x,dp;
is_composite(compose(ideal(x2+x,x14)));     // is_composite(x14+x7);
==> 1
is_composite(compose(ideal(x14+x,x2)));     // is_composite(x14+x2);
==> // -- Warning: wild case, cannot decide whether the polynomial has a
==> // -- decomposition goh with deg(g) divisible by char(basering) = 7.
==> -1