paGalt
   = pgThen4
        (\bar guard arrow expr -> (guard, expr))
        (pgItem Lbar)
        paExpr
        (pgItem Larrow)
        paExpr
paGalt
   = pgThen4
        (\bar guard arrow expr -> (guard, expr))
        (pgItem Lbar)
        paExpr
        (pgItem Larrow)
        paExpr
paGalt
   = pgThen4
        (\bar guard arrow expr -> (guard, expr))
        (pgItem Lbar)
        paExpr
        (pgItem Larrow)
        paExpr