isVeryAmple -- whether a divisor is very ample.

Synopsis

Usage:

isVeryAmple( D1 )
Inputs:
- D1, an instance of the type WeilDivisor,
Optional inputs:
- Verbose => a Boolean value, default value false, pass the verbose option to the called isEmbedding method
Outputs:
- a Boolean value,

Description

This function returns true if the divisor is very ample, otherwise it returns false. It works by calling isEmbedding from the RationalMaps package. If Verbose is set to true, it will print Verbose output from isEmbedding.

i1 : R = QQ[x, y, z]/ideal(x^3 + y^3 - z^3);

i2 : D = divisor(ideal(x, y-z));

o2 : WeilDivisor on R

i3 : isVeryAmple(D)

o3 = false

i4 : isVeryAmple(2*D)

o4 = false

i5 : isVeryAmple(3*D)

o5 = true

The output value of this function is stored in the divisor's cache.

Ways to use isVeryAmple :

isVeryAmple(WeilDivisor)

For the programmer

The object isVeryAmple is a method function with options.