President Chavez told the Assembly his proposals only affected 10% of the constitution.
A friend of mine said that there are certain things where a small change to the input doesn't necessarily create a small change in the output; his examples were genomes, software, and constitutions. I'd argue that genomes are basically a biological version of software. And is a constitution basically an operating system for a country? (I was able to find at least two example of this metaphor, from a constitutional law blog and at Wired, but I think I came up with it independently.) Change a few lines in the Constituion and you change a lot. The text of a lot of the amendments is quite short.
To this I would add mathematical proofs. I suspect that in most proofs, say, 90% of the thought is in 10% of the lines, the rest being (relatively) routine verification. A lot of mathematical formulas are also the same way -- change a single coefficient or a single sign and the formula doesn't work any more -- but those are sort of analysis to software, in that they're algorithms for solving some problem.