 Conditions  Trajectory Formulations 
 If  Straight line motion (see Lemma 1) 
 If   If   If  , , and (see Lemma 2 and Figure 10(a))  If )  , , and (see Lemma 3 and Figure 10(b))  If   If  , , and (see Lemma 4 and Figure 11(a))  If  , , , , and (see Lemma 5 and Figure 11(b))  If   If  , , and (see Figure 12(a))  If  , , and (see Figure 12(b))  If   If  , , and (see Figure 13(a))  If )  , , , , and (see Figure 13(b))  If  Path from to , with and (see Figure 14(a))  If  Path from to , with and (see Figure 14(b)) 
 If   If  Path from to , with and (see Figure 15(a))  If  Path from to , with and (see Figure 15(b))  If  Path from to , with (see Figure 16(a))  If  Path from to , with (see Figure 16(b)) 

