Input                  Should be parsed as             Derived constraint
                                                       on precedence
--------------------------------------------------------------------------------
\lambda x.x y          ((\lambda x.x) y)               lambda > apply
S x = y                  (= (S x) y)                   apply  > infix operators
\forall x.x=x	       (\forall x.(= x x))	       infix operators > binders
--------------------------------------------------------------------------------

Precedence total order:

  lambda > apply > infix operators > binders

where binders are all binders except lambda (i.e. \forall, \pi, \exists)