1.This is often a non-trivial procedure, and there are a lot of things that can go wrong even if your source code is correct.

What is the meanig of the word "non-trival'? My dictionary has no entry for this word.

Could anybody explain it?
I'd say it means "not trivial" or "not simple".

Look at this Wikipedia article:
When you see a word with a hyphen, try looking up just one part:

non - trivial = not - trivial. Look up trivial.

The real problem may be your ambivalence about the spelling.

You ask, What is the meanig of the word "non-trival'. I suspect you won't find trival in the dictionary. Did you try trivial? Be careful to look up the word as it is correctly spelled! Emotion: smile

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I like what dictionary.com says:

nontrivial adj.
Requiring real thought or significant computing power. Often used as an understated way of saying that a problem is quite difficult or impractical, or even entirely unsolvable ("Proving P=NP is nontrivial").

Having seen the phrase "source code" in your post, I think this definition is within context.
 CalifJim's reply was promoted to an answer.
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