Solve: If we request a non symbol and some symbol don't have numerical value in the expression, don't is solved

[latot]

Hi, well, one feature of Sympy its can request not only symbols, expressions too, like 2*x, but when some symbol in f don't have a numerical value we get an empty list:

>>> solve([Eq(x, y*2)], x*2)
[]
This works.
>>> solve([Eq(x*2, y*2)], x*2)
{2*x: 2*y}

Thx. Cya.