1 | initial version |
The number (11 - 1) / 2
is a rational number not an integer
sage: parent(5)
Integer Ring
sage: parent((11 - 1) / 2)
Rational Field
As these objects are of different nature, the operation is_prime
behave differently on each of them. You should consider using one of the two workaround
sage: is_prime( (11 - 1) // 2) # floor division returns integer
True
sage: is_prime( Integer( (11 - 1) / 2 ) ) # conversion Rational -> Integer
True
2 | No.2 Revision |
The number (11 - 1) / 2
is a rational number not an integer
sage: parent(5)
Integer Ring
sage: parent((11 - 1) / 2)
Rational Field
As these objects are of different nature, the operation is_prime
behave behaves differently on each of them. You should consider using one of the two workaroundworkarounds
sage: is_prime( (11 - 1) // 2) # floor division returns integer
True
sage: is_prime( Integer( (11 - 1) / 2 ) ) # conversion Rational -> Integer
True