Text: yes and i and i i got to thinking back when i was teaching college chemistry the people that took took you know the lower level courses i sometimes wondered you know are they really even educatable or trainable and it my God you know uh are the rest of us who went for the big bucks you know staying out of you know where where maybe we should be kind of socially obligated to spend some time teaching or something with these kids i don't know
Entailment: I taught college chemistry at one time.
Contradiction: I never taught anything in college at all.