Definition dependency analysis

tricu now allows defining terms in any order and will resolve
dependencies to ensure that they're evaluated in the right order.
Undefined terms are detected and throw errors during dependency
ordering.
For now we can't define top-level mutually recursive terms.

lib/base.tri

@@ -18,9 +18,9 @@ y = ((\mut wait fun : wait mut (\x : fun (wait mut x)))
 triage = \leaf stem fork : t (t leaf stem) fork
 test   = triage "Leaf" (\_ : "Stem") (\_ _ : "Fork")
 
-matchBool = (\ot of : triage 
-  of 
-  (\_ : ot) 
+matchBool = (\ot of : triage
+  of
+  (\_ : ot)
   (\_ _ : ot)
 )
 
@@ -35,44 +35,44 @@ emptyList? = matchList true (\_ _ : false)
 head = matchList t (\head _ : head)
 tail = matchList t (\_ tail : tail)
 
-lconcat = y (\self : matchList 
-  (\k : k) 
+lconcat = y (\self : matchList
+  (\k : k)
   (\h r k : pair h (self r k)))
 
-lAnd = (triage 
-  (\_     : false) 
-  (\_ x   : x) 
+lAnd = (triage
+  (\_     : false)
+  (\_ x   : x)
   (\_ _ x : x))
 
-lOr = (triage 
-  (\x     : x) 
-  (\_ _   : true) 
+lOr = (triage
+  (\x     : x)
+  (\_ _   : true)
   (\_ _ _ : true))
 
-map_ = y (\self : 
-  matchList 
-    (\_ : t) 
+map_ = y (\self :
+  matchList
+    (\_ : t)
     (\head tail f : pair (f head) (self tail f)))
 map = \f l : map_ l f
 
-equal? = y (\self : triage 
-  (triage 
-    true 
-    (\_   : false) 
-    (\_ _ : false)) 
-  (\ax : 
-    triage 
-      false 
-      (self ax) 
-      (\_ _ : false)) 
-  (\ax ay : 
-    triage 
-      false 
-      (\_ : false) 
+equal? = y (\self : triage
+  (triage
+    true
+    (\_   : false)
+    (\_ _ : false))
+  (\ax :
+    triage
+      false
+      (self ax)
+      (\_ _ : false))
+  (\ax ay :
+    triage
+      false
+      (\_ : false)
       (\bx by : lAnd (self ax bx) (self ay by))))
 
-filter_ = y (\self : matchList 
-  (\_ : t) 
+filter_ = y (\self : matchList
+  (\_ : t)
   (\head tail f : matchBool (t head) i (f head) (self tail f)))
 filter  = \f l : filter_ l f