Here we develop a number of techniques for multiparametric task creation. This problem arises if we build algorithmically close tasks of nearly equal hardness for probably simultaneous solving in the classroom with nearly the only difference in individual parameters. The set of parameters should be thick enough to avoid multiple collisions in the student flow of up to 100 people. And this requires no less than 10,000 variants. A curious aspect is that after such an abcd-task had been properly created one often has no need and sometimes has no obvious possibility to create principally different tasks of the same difficulty on the same topic. This circumstance along with multiple other conveniences of abcd-task makes it a connerstone of the learning process.