These are edge cases, such as ideals having no variables or a very
large number of variables, and special cases.

e1 - no variables, zero ideal
e2 - no variables, whole ring
e3 - one variable, zero ideal
e4 - one variable, whole ring
e5 - one variable, that var as generator
e6 - long variable name, large exponent
e7 - large number of variables, various special exponents
e8 - several variables, zero ideal
e9 - three independent blocks of generators
e10 - two variables, three generators
e11 - square-free ideal, circle of three elements, one non-minimal generator
e12 - two variables, zero ideal
e13 - two variables, whole ring
e14 - four variables, four pure powers
e15 - no variables, redundant 1 generators
e16 - several variables, whole ring
