Revision history [back]

I was trying to understand the structure of (a-b), where "a" and "b" were two very large expressions. So I was doing things like (a-b).simplify_full().factor(). I discovered the following anomaly.

     sage: var ('a', 'b')    #Adequate for illustration
    (a, b)
    sage: (a-b); (a-b).factor()
    a - b
    a - b
    sage: b=a               #By chance, "a" and "b" were equivalent. 
    sage: (a-b); (a-b).factor()
    0
    Traceback (most recent call last):
...
    ArithmeticError: factorization of 0 is not defined

I would have expected 0.factor() to give 0.

I was trying to understand the structure of (a-b), where "a" and "b" were two very large expressions. So I was doing things like (a-b).simplify_full().factor(). I discovered the following anomaly.

     sage: var ('a', 'b')    #Adequate for illustration
    (a, b)
    sage: (a-b); (a-b).factor()
    a - b
    a - b
    sage: b=a               #By chance, "a" and "b" were equivalent. 
    sage: (a-b); (a-b).factor()
    0
    Traceback (most recent call last):
...
    ArithmeticError: factorization of 0 is not defined

I would have expected 0.factor() to give 0.