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PORPAREN EQALOP and unbound variable and constructor errors in SML/ML
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copied!<p>Said I have got 2 CNF logical phrases a,b and my distrib function should return the CNF form of a|b (a OR b).</p> <p>Replacing rules that I've got are:</p> <pre><code>1) Replace p|(q&r) by (p|q)&(p|r) 2) Replace (q&r)|p by (q|p)&(r|p) </code></pre> <p>A prop defined this way:</p> <pre><code>datatype prop = Atom of string | Not of prop | And of prop*prop | Or of prop*prop; </code></pre> <p>The function:</p> <pre><code>local fun doOr(prop1,prop2) = (Or(prop1,prop2)) fun distrib1 (Or(Atom(sName1),Atom(sName2) ) ) = Or(Atom(sName1), Atom(sName2) ) |distrib1 (Or(Not(Atom(sName1) ),Atom(sName2) ) ) = Or(Not(Atom(sName1) ), Atom(sName2) ) | distrib1 (Or(Atom(sName1),Not(Atom(sName2) ) ) ) = Or(Atom(sName1), Not(Atom(sName2) ) ) | distrib1 (Or(Not(Atom(sName1)),Not(Atom(sName2) ) ) ) = Or(Not(Atom(sName1)), Not(Atom(sName2) ) ) | distrib1 (Or(prop1,And(prop2,prop3) ) ) = And( distrib1(Or(prop1,prop2) ), distrib1(Or(prop1,prop3) ) ) | distrib1 (Or(And(prop1, prop2), prop3) ) ) = And( distrib1(Or(prop1,prop3) ), distrib1(Or(prop2,prop3) ) ) in fun distrib (prop1,prop2) = distrib1(doOr(prop1,prop2) ); end; </code></pre> <p>Well, I don't know if the function itself is right although I just went through all the base options and the replacing rules but for now I get the above errors when the EQALOP appear after the distrib1 function and the constructors error appear the distrib function.</p> <p>Why I get those errors? I am not sure but maybe I am supposed to use let and not local but then how can I transform it to a let structure?</p> <p>Thanks.</p>

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