MAYs and MUSTs

[jyasskin]

The current spec has:

1. Let pendingResult be false.
2. If isInputPendingOptions is undefined, assign it to a newly-instantiated IsInputPendingOptions with the default constructor.
3. The user agent MAY at this step continue to step 5 for any reason.
4. If the surrounding agent's event loop has any task queues that contain a task that will dispatch an event that is a UIEvent or TouchEvent or a child of either, or if the user agent determines that it MAY soon enqueue such a task, and the dispatched event would have an EventTarget that exists within a window of the same origin, then the user agent MUST run the following steps:
   1. If the user agent considers the task to be a continuous event task and isInputPendingOptions.includeContinuous is false, continue to step 5.
   2. The user agent MAY let pendingResult be true.
5. Return pendingResult.

The

• MAY at this step continue to step 5 for any reason.
• MAY let pendingResult be true.

are redundant, and

• MUST run the following steps:

is somewhat inconsistent.

It looks like you're trying to say that isInputPending MAY return false even when the correct answer is true. In that case, just make the first step:

1. The user agent MAY return false.

And write the rest of the steps as if it's trying to give an accurate answer.

https://infra.spec.whatwg.org/#algorithm-conformance says you can replace "then the user agent MUST run the following steps:" by just "then:".