1
vote
2answers
59 views

Changing a tag when one function is passed into another using UpValues

I have two complicated functions f[x,y] and g[t]. Before the main evaluation code in ...
10
votes
2answers
210 views

Why isn't Lookup treated like other symbols?

With Mathematica 10, I wanted to overload Lookup using TagSetDelayed, but it doesn't work. For instance, if I define two objects ...
10
votes
3answers
306 views

How can I hold UpValues but evaluate other expressions?

Consider these definitions: own = "OwnValue"; down[_] = "DownValue"; sub[_][_] = "SubValue"; N[n] = 3.14; _[___, up, ___] ^= "UpValue"; The attribute ...