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Date: Wed, 25 Feb 2015 23:04:10 +0000
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From: Jeremy Yallop <yallop@gmail.com>
To: Martin DeMello <martindemello@gmail.com>
Cc: OCaml List <caml-list@yquem.inria.fr>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [Caml-list] "this ground coercion is not principal"

On 25 February 2015 at 21:35, Martin DeMello <martindemello@gmail.com> wrote:
> I'm still curious about where the term "ground coercion" came from,

It comes from the term "ground type".  A ground type is a type which
doesn't contain type variables, like the types 't' and 'int' in the
example.