detectCongruence -- detect and return a congruence of secant curves to a surface

Ways to use detectCongruence:

• detectCongruence(HodgeSpecialFourfold)
• detectCongruence(HodgeSpecialFourfold,ZZ)
• detectCongruence(SpecialCubicFourfold) -- see detectCongruence(SpecialCubicFourfold,ZZ) -- detect and return a congruence of (3e-1)-secant curves of degree e
• detectCongruence(SpecialCubicFourfold,ZZ) -- detect and return a congruence of (3e-1)-secant curves of degree e
• detectCongruence(SpecialGushelMukaiFourfold) -- see detectCongruence(SpecialGushelMukaiFourfold,ZZ) -- detect and return a congruence of (2e-1)-secant curves of degree e inside a del Pezzo fivefold
• detectCongruence(SpecialGushelMukaiFourfold,ZZ) -- detect and return a congruence of (2e-1)-secant curves of degree e inside a del Pezzo fivefold

For the programmer

The object detectCongruence is a method function with options.

The source of this document is in SpecialFanoFourfolds.m2:3349:0.