eq_point: _ = _
eq_line: _ = _
eq_plane: _ = _
inc_po_l: the point _ is incident to the line _
inc_po_pl: the point _ is incident to the plane _
inc_l_pl: the line _ is incident to the plane _
int_l_l: the lines _ and _ intersect
int_l_pl: the line _ and the plane _ intersect
int_pl_pl: the plane _ and the plane _ intersect
col: the points _, _ and _ are collinear
comp: the points _, _, _ and _ are coplanar
bet: the point _ is between the points _ and _
cong: the segment (_, _) is congruent to the segment (_, _)

~eq_point: _ != _
~eq_line: _ != _
~eq_plane: _ != _
~inc_po_l: the point _ is not incident to the line _
~inc_po_pl: the point _ is not incident to the plane _
~inc_l_pl: the line _ is not incident to the plane _
~int_l_l: the lines _ and _ do not intersect
~int_l_pl: the line _ and the plane _ do not intersect
~int_pl_pl: the plane _ and the plane _ do not intersect
~col: the points _, _ and _ are not collinear
~comp: the points _, _, _ and _ are not coplanar
~bet: the point _ is not between the points _ and _
~cong: the segment (_, _) is not congruent to the segment (_, _) 
