Follow-up to Alex's post about PI: CALL applied to the strings like "INKEY$", "MPSTAT", "MPNAME$", "PRGNAME$", "DISPLAY" - other system functions that take no parameters - appears to use the system functions. CALL applied to the string "PI" uses the user-defined DEF PI(). It was silly to make it a function in Petit Computer, and it was silly to make the same mistake in SmileBasic.