algebras Kolsasbanen Sognsvannsbanen Urata 9502 types intuitionistically supersymmetric rQundO WQpbl VQundA UQppVQppZ SCHELL OQppPQppRQppS MCGREEVY KQppL HQppI DLAMINI intuitionistic equations Oohira Seki PORTER constant Oizumi closed C0