*This is from a talk by Edsger W. Dijkstra, "[How Computing Science created a new mathematical style](https://www.cs.utexas.edu/users/EWD/transcriptions/EWD10xx/EWD1073.html)", 4 March 1990:*

> 
> Almost all formalisms used daily by the classical mathematician are at least ambiguous. But that does not hurt the classical mathematician because he does nothing with a formula without interpreting
>  it and part of his professional competence consists in subconsciously rejecting all unintended interpretations. (If you show him
> 
> 
> sin($\alpha+\beta$) versus sin(s+i+n)
> 
> 
> it depends on his sense of humour whether he is amused.) The manipulation of uninterpreted formulae requires unambiguous formalisms [...]
> 
> 
> 

Tragically, I am not *quite* sure what is so funny. Concatenating three English letters together with plus signs to make a function name is amusing I suppose, but I get the feeling there is more going on here, and I am not able to put it into words.

Is anyone able to explain these expressions, and why they could be considered humorous?