⎕PP is used to format numbers displayed directly. It is an implicit argument of monadic function Format (⍕), monadic ⎕FMT and for display of numbers via ⎕ and ⍞ output. ⎕PP is ignored for the display of integers.
⎕PP←10 ÷3 6 0.3333333333 0.1666666667 ⎕PP←3 ÷3 6 0.333 0.167
If ⎕PP is set to a value ≥17 (when ⎕FR is 645) or 34 (when ⎕FR is 1287), floating-point numbers may be converted between binary and character representation without loss of precision. Then, if ⎕CT is 0 (to ensure exact comparison), for any floating-point number N the expression N=⍎⍕N is true.