eliminate h1 with h4 h5
p q r al_ac betty_beg carl_cac : Prop
h1 : al_ac ∧ (betty_beg ∨ carl_cac)
h2 : betty_beg → ¬al_ac
h3 : carl_cac → betty_beg
⊢ False
case intro
p q r al_ac betty_beg carl_cac : Prop
h2 : betty_beg → ¬al_ac
h3 : carl_cac → betty_beg
h4 : al_ac
h5 : betty_beg ∨ carl_cac
⊢ False