A sequence is a pattern of boolean expressions spread across clock cycles. A boolean expression is a one-cycle sequence, delays glue expressions across time, repetition compresses repeats, and composition combines patterns.

One model explains every operator below. A ranged delay or repetition forks a match thread per legal choice, and the sequence matches when any thread reaches its end.

Every lesson below ends with a bench that runs real assertions on Verilator 5.048 with planted bugs. Verilator checks single-thread sequences correctly: fixed delays, a range at the very end, written-out repetition, throughout over a fixed window. Sequences that fork and then continue (a range or goto followed by more, repetition or and in a consequent) compiled and missed some or all planted failures, while covers on the same sequences counted correctly. The benches show the compact form's count beside a form that works, and What the Open Simulators Run lists every case.