An income tax is levied on any income that exceeds deductions.

The tax agent allowed the deduction.

It is a mistake to confound strangeness with mystery. The most commonplace crime is often the most mysterious, because it presents no new or special features from which deductions may be drawn.

That was a brilliant deduction. I did not expect you to solve the mystery so quickly.

I had no keener pleasure than in following Holmes in his professional investigations, and in admiring the rapid deductions, as swift as intuitions, and yet always founded on a logical basis with which he unravelled the problems which were submitted to him.

The program allows pre-tax deduction of the cost of a monthly transit pass.

Your hand stole towards your own old wound and a smile quivered on your lips, which showed me that the ridiculous side of this method of settling international questions had forced itself upon your mind. At this point I agreed with you that it was preposterous and was glad to find that all my deductions had been correct.