feat: Implement chapter 8

trans/chap8.str

@@ -0,0 +1,12 @@
+module chap8
+imports signatures/-
+
+rules
+
+   SwapWithPat = ?Or(e1,e2); !Or(e2,e1)
+   SwapAnon = (Or(e1,e2) -> Or(e2,e1))
+   NoSwapTwice = (Or(e1,e2) -> Or(e2,e1)); (Or(e1,e2) -> Or(e2,e1))
+   OkSwapTwice =
+     {e3,e4 : (Or(e3,e4) -> Or(e4,e3))}; {e3,e4 : (Or(e3,e4) -> Or(e4,e3))}
+   TermWrap = !Or(<id>, Not(<id>))
+   TermProj = ?Or(_, Not(<id>))

trans/spoofax_propositional_language.str

@@ -15,6 +15,7 @@ imports
   prop-desugar
   chap6
   chap7
+  chap8
 
 rules // Debugging