Blanking a corner of plot

Problem:

I want to blank my contour plot only in the lower left-hand corner where x < 45 AND y < 30.

Solution:

You can use equations like the ones below to create a blanking variable equal to 0 only if x < 45 and y < 30. Then you can delete the extra variables {lowerx} and {lowery}.

{lowerx} = max (x -45, 0)

{lowery} = max (y – 30, 0)

{blank} = {lowerx} + {lowery}