Except that "del" is also (and I think more commonly) the name for the upside-down Delta used in vector calculus for div, grad and curl. (I usually say "partia

Except that "del" is also (and I think more commonly) the name for the upside-down Delta used in vector calculus for div, grad and curl. (I usually say "partial dx by dt" or whatever, which seems OK to me.)