# isElliptic -- A method to check if an ideal defines an elliptic curve.

## Synopsis

• Usage:
isElliptic(I)
• Inputs:

## Description

Given a non-homogeneous ideal in two variables check if it represents a

 i1 : S=ZZ/7[x,y] o1 = S o1 : PolynomialRing i2 : I=ideal(y^2-x^3-x-1) 3 2 o2 = ideal(- x + y - x - 1) o2 : Ideal of S i3 : isElliptic(I) o3 = true

## Ways to use isElliptic :

• "isElliptic(Ideal)"

## For the programmer

The object isElliptic is .