When I open a brand new sketch in Arduino/Teensiduino and enter "float y0;" as the first line, this error occurs after verify:
""float y0" redeclared as different kind of symbol".

This doesn't occur when the line is "float x0" or "float z0;". It doesn't occur when the board is set to Arduino Uno, but it does happen when set to Teensy 3.6, Teensy 4.0, and Teensy 3.1/3.2.

Is "y0" a reserved variable name?