He doesn't use `'
`define `gcd a b'
`let ``r `modulo a b'''
`if `= 0 r'
b
`gcd b r''''
'''
Just look at how terse, how elegant. You get rid of the lots of irritating silly parentheses.
Problem is with quote and quasi-quote.I suggest HELL:α and FUCKING-HELL:α for 'α and `α respectively.