isequal of two unit vpa precisions

[cbm755]

I think the isequal behaviour has changed between SymPy 1.12 and the main branch.

With SymPy 1.13.dev:

>> isequal (vpa (1, 16), vpa (1, 32))
ans = 0

But on 1.12:

>> isequal (vpa (1, 64), vpa (1, 32))
ans = 1

In both cases:

>> vpa (1, 32) == vpa (1, 64)
ans = (sym) True

• what is correct?
• what has changed upstream?
• we should add unit tests for whatever we prefer here.

Related: logspace is failing a test b/c of this.

[cbm755]

Upstream issue: sympy/sympy#26146

Looks like their intention is that Float(1, 32) would not equal to Float(1, 64). Good.

(our == is more like SymPy Eq IIRC).