Add some convenience exports to Syntax.elm

src/Bergamot/Syntax.elm

@@ -1,4 +1,4 @@
-module Bergamot.Syntax exposing (Term(..))
+module Bergamot.Syntax exposing (Term(..), instantiate, emptyInstantiationState, unify, emptyUnificationState)
 
 import Set exposing (Set)
 import Dict exposing (Dict)
@@ -21,6 +21,8 @@ type alias InstantiationState =
     , vars : Dict Metavariable UnificationVar
     }
 
+emptyInstantiationState = { counter = 0, vars = Dict.empty }
+
 metavariable : Metavariable -> InstantiationState -> (UnificationVar, InstantiationState)
 metavariable mv is =
     case Dict.get mv is.vars of
@@ -54,6 +56,8 @@ type alias UnificationInfo =
 
 type alias UnificationState = Dict UnificationVar UnificationInfo
 
+emptyUnificationState = Dict.empty
+
 reconcile : Set UnificationVar -> Maybe (Term UnificationVar) -> UnificationState -> UnificationState
 reconcile eq mt us =
     let newValue = { equivalence = eq, term = mt }