If the integral closure of R has not yet been computed, that computation is performed first. No extra computation is involved. If R is integrally closed, then the identity map is returned.
R = QQ[x,y]/(y^2-x^3) |
icMap R |
This finite ring map can be used to compute the conductor, that is, the ideal of elements of R which are universal denominators for the integral closure (i.e. those d ∈R such that d R’ ⊂R).
S = QQ[a,b,c]/ideal(a^6-c^6-b^2*c^4); |
F = icMap S; |
conductor F |