@txnelson gave you a working example but I can explain what you've got wrong in your attempts.
If (0.50 < ( :Name( "P1-R1-D1-L1" ) > 2.0), "True", "False")
In this on you're trying a complex comparison that JMP doesn't support, namely a < b > c, i.e. a less than b greater than c.
Looking in the Formula Editor you can see the complex comparisons that JMP does offer, and that @txnelson used:
Notice the help text which gives a clue that JMP is a functional language and that these complex operators are really shorthand for the functions Less LessEqual() and LessEqual Less(). JMP doesn't have a function for the comparison you wanted to make.
For the second attempt:
If (0.50 < ( :Name( "P1-R1-D1-L1" ))|(2.0 > ( :Name( "P1-R1-D1-L1" ), "True", "False"))
You've got some more parentheses than needed and they are in the wrong places. Here's a corrected version:
If( 0.50 < :Name( "P1-R1-D1-L1" ) | 2.0 > :Name( "P1-R1-D1-L1" ),
"True",
"False"
)
However, let's consider what you're asking for in this logical comparison. You're asking JMP to check whether your column is greater than .5 or 2.0 is greater than your column. This will be true for all values of your column. If your column is less than .5, then 2.0 will be greater than your column. If your column is greater than 2.0 then .5 will be less than your column.
So, you probably want the version that @txnelson provided, checking to see if your column is within the range .5 to 2.0 using the a < b <= c construct.
-Jeff