Maple: How do I type "solve" with an arrow under?

Question

I am trying to learn using Maple 18 (Mac). I have defined a function with a list of X and Y values.

f := x->LinReg(X, Y, x)

Now I would like to output the unknown "x" value that correlates with a known "y" value (e.g. 30). According to the instruction manual, that I have, the way to do it is using this command:

I just can't figure out how to type "solve" with an arrow under it.

Any help would be appreciated.

EDITED: Screenshot of the commandwindow

Answer 1

LinReg seems to be a command in some special package Gym, which is not part of standard Maple.

But here is what I might do using standard Maple.

> with(Statistics):
X:= [-3,-1, 1, 2,4];
Y:= [-1,0.5,5, 6,8];
F:= LinearFit(a*x+b, X, Y, x);

$$ F := 1.38356164383562\; x+2.86986301369863$$

> solve(F = 30, x);

$$19.60891089$$

Answer 2

I think either the installed expansion package "Gym" or Maple might have been acting up, because after a lot of help from @JEET TRIVEDI, we where able to rule out the inputted commands. I restarted Maple and then It "magically" worked. Problem solved. Thanks to everybody who helped me solve the problem.