This class is used to manipulate any kind of Equality.
An Equality can have several members, like in 3×2 + 1 = 6 + 1 = 7
So far, it was complicated to let Equation inherit from Equality and not much of interest. It might be done so later.
Possible args for __init__():
Option:
equal_signs=["="|"neq"]
This provides a list of equal/not equal signs. Must be as long as the length of the list given in argument, minus 1. Later this may contain signs like greater than, less than etc.
Fields:
elements: (read-only) the different members of the Equality
equal_signs: (read-only) the signs to use between the Exponented ("="|"neq")
Note that len(equal_signs) == len(elements) - 1
Debugging info: no dbg_str() method, so far