Cynicistic Paradox

Its 9:40 in the night.16 pairs of eyes were looking at the doorway.
Professor is late . late by 10 min. It not unusual, but a day before independence day and that too in the night for a class that's going to stretch for the next,if unfortunate, one and half hours, it is a close call of limits.

They were not disappointed.

Like a storming wind he barged in . Plugged in the lap top and the show began.

Straight on the board. "If we fail to prove something then Negation of that something is assumed to be true"

"I want you all to analyse this statement and come up with the meaning " . he asked in a low whisper like voice.

He wondered whether it was really a technical course or some course of psychology that he was attending.

"Are the resources introduced into subject of being failed" somebody from the left of him asked.
"What???" his stomach started to roll, what did he mean...

"You are provided with infinite time and space for the quest." He answered while cleaning his black rimmed spectacles.

"What is the idea of being true? I mean how do you judge what is true" .
"Vidyut, truth is the deduction based on the facts" professor said with a wink.

"In the absence of any evidence to the contrary a proposition is assumed to be true".
somebody from the back row shouted.

Bingo! he said with his usual tinker of both index fingers.

"So what does that prove....?"

But sir..." came a low husky kind of voice , with a low confident note from the right corner.

"yes...". professor was getting impatient.

"I think that sentence itself is contradicting"

everybody turned back.
"another nerd" he thought.

"And how it may be .." Prof was curious.
"because if we fail to prove something , for negation of that something to be true ...it should be false for that something." He said with an air of supremacy.

The class dropped into pin drop silence.

The professor just stared into the board. You could hear the ululation of the fan.