This is called <math>F_2 \ </math>, the free group on two generators. Any group structured like this, in which ''a'' and ''b'' have infinite order and are independent, (ie, no combination of ''a'' and ''b'' form ''e'') is this group. We can picture this group graphically, with ''a'' and ''b'' axes: | This is called <math>F_2 \ </math>, the free group on two generators. Any group structured like this, in which ''a'' and ''b'' have infinite order and are independent, (ie, no combination of ''a'' and ''b'' form ''e'') is this group. We can picture this group graphically, with ''a'' and ''b'' axes: |