do not create symmetric functions that are equal and different from 0 #34576
Description
┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 9.7, Release Date: 2022-09-19 │
│ Using Python 3.10.5. Type "help()" for help. │
└────────────────────────────────────────────────────────────────────┘
sage: s = SymmetricFunctions(ZZ).s()
sage: f = s(0/2); f
0
sage: f == 0
False
sage: f._monomial_coefficients
{[]: 0}
Component: combinatorics
Keywords: symmetric functions
Author: Martin Rubey
Branch: e6ae236
Reviewer: Travis Scrimshaw
Issue created by migration from https://trac.sagemath.org/ticket/34576