Binary Quadratic Forms (New Chapter) [HB 58]

New features:

• A comprehensive treatment of the class group of nonfundamental quadratic forms.
• Natural homomorphisms from forms of nonfundamental discriminant to those of fundamental discriminant.
• The function FundamentalQuotient is the homomorphism of class groups to the forms of fundamental discriminant. The function QuotientMap(Q1,Q2) is the homomorphism of forms of discriminant D₁ = m² D₂ to forms of discriminant D₂.
• Natural coercion (via !) from forms of discriminant D₁ = m² D₂ to forms of discriminant D₂.
• Analysis of the 2-torsion subgroup (function TwoTorsionSubgroup) and the enumeration of its elements (function AmbiguousForms).
• Analysis of Sylow p-subgroup structure (function pSubgroup).