AQA 7517 4.4.2.2: Maths for regular expressions
The free BugBot lessons that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
A finite state machine sorts strings into those it accepts and those it rejects. The strings it accepts form a set, and the precise way to talk about the languages of machines, regular expressions and grammars is set notation. This lesson is the maths the next three lessons stand on. You have used lists since GCSE; a set is different in two ways that matter.
- What a set is
- Set comprehension
- Finite and infinite sets, and cardinality
- Cartesian product
- Subsets and set operations
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- A6.3 Sets Theory of computation
Set notation and comprehension, finite and countably infinite sets, cardinality, Cartesian product, subsets, union, intersection and… - A6.10 Project: the mission robot Theory of computation
Validate a mission with a regular expression, carry it out with a Mealy machine, and report with sets.
Try it on a robot
The task from A6.3 Sets, running here. Change the program and press Run.
The specification is AQA's own document; this page says which of our lessons teach point 4.4.2.2 and is not endorsed by the board.