Mathcad 15 has a gradient function, "cntrl-shift G".
The others have been posted by users, good luck with your search.
I don't see anything that indicates
Welcome to the world of PTC!
This Mathcad forum exists quite a long time and was formerly hosted by Mathsoft, the original makers of Mathcad. After PTC bought the program from Mathsoft, the forum was "migrated" two or three times. This was done so poorly by PTC that most attachments in older posts got lost, links in the forum posts referencing another post got invalid, posts got lost altogether, the subforum structure was destroyed, etc. An impressive prove of PTC's incompetence and ignorance and the reason for the fact, that this forum now is just a mess and not the source for solutions and inspirations it used to be in former times.
Thats the explanation why you can't see the attachments which are mentioned in this old thread - they simply aren't here any more and will never come back.
In case you really are interested in implementing curl or div, you are better off in creating a new thread with your question, stating exactly what you have in mind and which version of Mathcad or Prime you are using.
In case you are using real Mathcad (=Mathcad 15 and below) you may go to "Help-Quicksheets-Calculus and DiffEQs-Gradient,Divergence and Curl" for an implementation of those operators for scalar valued vector functions.
EDIT: For whatever it may be worth I made a pdf of the aforementioned quicksheet and attach it here