Re: [Sml-implementers] equality type variables in datatype declaration

[Peter S. <se...@di...>]

> Should this program be accepted or rejected?
> 
> 	datatype ''a t = T of ''a
> 	val _ = T 13.0

According to the Definition it should be rejected, we concluded in
1995 when reading the (1990) Definition carefully.  Indeed Moscow ML
retains the eq-ness of the type parameter ''a in the type function and
therefore rejects
   
        val _ = T abs

When it does not reject 

  	val _ = T 13.0

is because real does admit equality in Moscow ML.  So Moscow ML and
SML/NJ accept the declarations for different reasons...

Peter