paLamExpr
   = pgThen4
        (\lam patterns arrow rhs -> ExprLam patterns rhs)
        (pgItem Lslash)
        (pgZeroOrMore paAPat)
        (pgItem Larrow)
        paExpr
paLamExpr
   = pgThen4
        (\lam patterns arrow rhs -> ExprLam patterns rhs)
        (pgItem Lslash)
        (pgZeroOrMore paAPat)
        (pgItem Larrow)
        paExpr
paLamExpr
   = pgThen4
        (\lam patterns arrow rhs -> ExprLam patterns rhs)
        (pgItem Lslash)
        (pgZeroOrMore paAPat)
        (pgItem Larrow)
        paExpr