Complex sentence: West Texas is a loosely defined part of the state of Texas, United States, generally encompassing the arid and semiarid lands west of a line drawn between Fort Worth and Del Rio, Texas.
Split into simpler sentences: West Texas is a vernacular term applied to a large region of the state of Texas, United States. Its boundaries are subject to debate but generally encompass the arid and semiarid lands west of a line drawn between Fort Worth and Del Rio, Texas.