# No space between overline and letter in Math

Hello,

when I use this formula `P_{overline F}( overline M )={P( overline {M} intersection overline F)} over { P(overline {F})}=2 over 7`

there is not enough space between the overline and the letter. Especially the overline in the subscript is not visible.
How can I fix this?
C:\fakepath\Probleme_Overline.odt