Depending only on formalthinking, Euclid formed system through figure proof, firstly applied the fifth postulate in the 29th proposition.
欧几里德仅仅依靠形式思维，通过图形佐证形成体系，在第29个命题中首先运用第五公设。
2
One way of thinking of patterns is as bits of advice from experienced practitioners, except that advice happens to be documented in a formal publication.
思考模式的一种方式是将其当作经验丰富的从业者的建议，除非建议碰巧出现在了正式的出版物中。
3
I am not thinking of mere forms of politeness, such as saying "please" and "thank you" : formal manners are most fully developed among barbarians, and diminish with every advance in culture.