# Interesting extracts from Gobel, Bach, Escher

## SMC

DNA is like SMC.

Lisp macros that produces more lisp macros.

## Logic axioms

A: If two sides are equivalent to some side, they are equal B: Two sides of the triangle are equal to the same Z: Two sides of this triangle are equal to each other

We say that if A, B, are true, we can say that Z is true logically. <- how can we say this is true?

A: If two sides are equivalent to some side, they are equal B: Two sides of the triangle are equal to the same C: If A, B then Z Z: Two sides of this triangle are equal to each other

Where we if we believe A, B, C then Z. <- how can we say this is true?

A: If two sides are equivalent to some side, they are equal B: Two sides of the triangle are equal to the same C: If A, B then Z D: If A, B, C, then Z Z: Two sides of this triangle are equal to each other

We see that this leads to an endless series of questions, and we never reach Z.