Christian Gollwitzer <auriocus at gmx.de>: > Am 03.07.16 um 13:01 schrieb Marko Rauhamaa: >> Alain Ketterlin <alain at universite-de-strasbourg.fr.invalid>: >>>>> It would be very confusing to have a variable named ∇f, as confusing >>> as naming a variable a+b or √x. >>>> Scheme allows *any* characters whatsoever in identifiers. >> Parentheses? Yes. Hint: Python allows *any* characters whatsoever in strings. Marko