While reading an answer to a different question i encountered the statement of the heading; that is "...the fundamental group of the Projective line is of order 2; then taking the homomorphism...etc."
My (rather dumb) question is regarding the order 2 of the related fundamental group: what does it means for a linear group to be of order n?**
What is the order of the fundental group of a projective plane P2?
Thanks in advance. Greetings
**Does it have something to do with the cyclical-subspaces of a linear transformation T, the direct-sum of n-invariant subspaces, etc?