Definition of Formal
A mock dictionary entry noting that 'formal' in math research ('formal computation') means hand-wavy, the opposite of the everyday meaning.
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Free for classrooms, worksheets, slides and other non-commercial use under CC BY-NC 4.0, with credit to Ben Orlin.
Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2018-05-02-definition-of-formal/ (CC BY-NC 4.0)Transcript
"FORMAL — adjective. 1. Official; fancy; like a tuxedo or ball-gown. 2. (math research) Sloppy; nondefinitive; hand-wavy."
[Caption] "There are sins against language for which the mathematicians cannot be forgiven."