# Argument selection for T700 This is one named real quantity, Bloch's elliptic dilogarithm. Its real companion J and the elliptic trilogarithms are separate quantities, not additional values of a form parameter. The marked torus and ordered integer parameters (Delta,N,r,s) follow family issue 311. All logarithms are natural. Set b=0 for Delta divisible by four and b=1 otherwise, tau=(-b+i sqrt(|Delta|))/2 and u=(r tau+s)/N; preserve the sign in q=exp(2*pi*i*tau). No modular replacement of the marking is made. * Delta has role arithmetic_structure. The thirteen selected discriminants -3,-4,-7,-8,-11,-12,-16,-19,-27,-28,-43,-67,-163 are exactly the imaginary quadratic orders of class number one, equivalently rational singular modulus. Nonmaximal orders are included. This is a complete arithmetic slice, independently supported by T83 and Sage's cm_orders(1) documentation. Higher class numbers require ideal-class choices and are deferred, not silently collapsed onto principal representatives. Both rectangular and rhombic lattices and the extra-automorphism cases occur. * N has role discrete_index. It is the exact finite order of a point, not a renamed continuous argument. The reference extent N<=6 is noncanonical. Orders 3,4,6 appear in Guillera–Rogers Theorem 4. Order 5 gives the next prime group; order 6 includes the first mixed-prime group. The purpose is recognition of torsion regulator values and finite-group comparisons. No individual application is asserted for every pair (Delta,N). The origin and order 2 give identically zero D_q and are omitted by proof, not a numeric threshold. * r and s jointly have role arithmetic_structure, as coordinates in E[N]. They are not independently sampled real arguments: 0<=r,s