Analytic l ∨ m = > l∧α

Prove that if l∨m,

∵l？ α，m？ α

∴l∥α (judgment theorem of line-plane parallelism)

l∩α≦& gt； l∑m

When L∧α, l and m are parallel or different.

∴l∥m is a necessary and sufficient condition for l∧α.