or x y, or x || y, is the boolean "or" operation (not to be confused
with Or : Prop → Prop → Prop, which is the propositional connective).
It is @[macro_inline] because it has C-like short-circuiting behavior:
if x is true then y is not evaluated.
and x y, or x && y, is the boolean "and" operation (not to be confused
with And : Prop → Prop → Prop, which is the propositional connective).
It is @[macro_inline] because it has C-like short-circuiting behavior:
if x is false then y is not evaluated.