If ¯¯¯¯¯¯¯¯AB≅¯¯¯¯¯¯¯¯¯CD, and ¯¯¯¯¯¯¯¯¯CD≅¯¯¯¯¯¯¯¯EF, then ¯¯¯¯¯¯¯¯AB≅¯¯¯¯¯¯¯¯EF is a ___________ property of congruence.
Out of the three lines AB, CD and EF, if AB is parallel to EF and CD is also parallel to EF, then what is the relation between AB and CD.