I incountered the following problem:
My input is f[x,underscore-]:=x^2, when I want to calculate f the output was f. This example is in the book, so what mistake i did? or what is wrong with my program?
My input was :
RecFrame[x,y,u,v all underscored]
Also I had not found any respond. Can I get your Kind help in this aspect? thank you.