adamc@88: signature S = sig
adamc@88:         con nm :: Name
adamc@88:         con r :: {Type}
adamc@88: 
adamc@88:         constraint [nm] ~ r
adamc@88: end
adamc@88: 
adamc@88: structure M : S = struct
adamc@88:         con nm = #A
adamc@88:         con r = [B = float, C = string]
adamc@88: 
adamc@88:         constraint [A] ~ [B]
adamc@88:         constraint [nm] ~ r
adamc@88:         constraint [C] ~ [D]
adamc@88: end
adamc@88: 
adamc@88: structure M' = struct
adamc@88:         open M
adamc@88: 
adamc@88:         con combo = [nm = int] ++ r
adamc@88: end
adamc@88: 
adamc@88: structure M' = struct
adamc@88:         open constraints M
adamc@88: 
adamc@88:         con nm' = M.nm
adamc@88:         con r' = M.r
adamc@88:         con combo = [nm' = int] ++ r'
adamc@88: end
adamc@89: 
adamc@89: 
adamc@89: signature S' = sig
adamc@89:         con r1 :: {Type}
adamc@89:         con r2 :: {Type}
adamc@89: 
adamc@89:         constraint r1 ~ r2
adamc@89: end
adamc@89: 
adamc@89: functor F (M : S) : S' = struct
adamc@89:         con r1 = [M.nm = int]
adamc@89:         con r2 = M.r
adamc@89: 
adamc@89:         open constraints M
adamc@89:         constraint r1 ~ r2
adamc@89: end