Min, max, ceil, floor in ParameterExpression

[eggerdj]

What is the expected enhancement?

Support functions min, max, ceiling, and floor in ParameterExpression.

Discussion points

ParameterExpression will support comples numbers: #5192.

min and max are not well defined for complex numbers (ceiling and floor do not have this characteristic). A possible implementation could use Sympy and allow Sympy to raise errors. For example:

import sympy as sym
x = sym.Symbol('x', complex=True)
y = sym.Max(x*1.0j, -2)
y.subs(x, 1.0j)  # This works and returns -1
y.subs(x, 1.0)  # This raises ValueError: The argument '1.0*I' is not comparable.

[mrvee-qC]

Update for Santa:elf:- QGoGP

✅ PR #5278 Seems to address this and is awaiting approval for being merged!

Will update comment/add more comments if cause is found/fixed!

Python version 3.9.7
qiskit-terra version: 0.19.1