<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Apr 1, 2021, at 8:12 PM, Anthony Clayden <<a href="mailto:anthony_clayden@clear.net.nz" class="">anthony_clayden@clear.net.nz</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="caret-color: rgb(0, 0, 0); font-family: arial, sans-serif; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: pre-wrap; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Can I user-define a conventional type-class that behaves more like `(~)`?</span></div></blockquote></div><br class=""><div class="">I don't think so.</div><div class=""><br class=""></div><div class="">But why does this matter? I can't define `Char` in user code, but it's exported from the Prelude and requires no extensions. While I can define Eq in user code, I can't make `deriving` work with my version. I can't define `error` in user code. There are many others, I'm sure.</div><div class=""><br class=""></div><div class="">So: why does this matter?</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Richard</div></body></html>