Associated lessons (alternating half-groups)

Associated lessons are two simultaneous half-group lessons that alternate consecutively. The typical case:

Slot 1: group A in biology,  group B in physics
Slot 2: group A in physics,  group B in biology

Both groups have covered both subjects after the two slots, but in a different order. This structure is very common in experimental sciences (biology labs + physics labs with two specialist teachers who "rotate"), in the arts (one half-group in practice, the other in theory, then they swap), etc.

Creation

1. First create two concatenated lessons (one under the other).
2. Hover over the boundary between the two: an "association" button appears.
3. Click it and designate the two groups that must alternate — ideally declared as a class division.

Consistency with groups

The groups used in an association must be declared as a class division in the class — otherwise the solver raises a consistency warning (a group cannot be in two places at the same time).