- David Hilbert
put maths to alogo
provable statement
- Kurt
statement it nt provble
you prove sth is false
it 's true but no provable
formal definiton
- Alonzo Church
lambda calculus
halting proble
- Kurt
second definition
the same as you
- Alan Turing
Turing Machine
als equal
computer = turing machine
all three same
mathematic invented or discovered?
you discover!
Part II Propositions as types
- Gerhard Gentzen
Natural Deducion
implication
elimination rules
A proof
know A and B, i can know B and A
a formal proof
simplifying proofs
sub formular
formulars ->
proof can be simpled
听不懂，放弃了