Proton Mail does not allow users to search for emails based on label combinations using boolean logic.

I want to be able to search for emails that have both "Label A" AND "Label B".
And I want to be able to search for emails that have "Label A" but exclude those that also have "Label B".
No Field Syntax: The advanced search syntax documentation lists operators for text, phrases, and wildcards, but lacks a label: field prefix (e.g., label:work, !label:sales) to target the label specifically.