diff --git a/lib/imbecile.rb b/lib/imbecile.rb
index 1473025..737e779 100644
--- a/lib/imbecile.rb
+++ b/lib/imbecile.rb
@@ -2,17 +2,17 @@ require "erb"
 require "set"
 require_relative "imbecile/cli"
 require_relative "imbecile/code_point_range"
+require_relative "imbecile/fa"
+require_relative "imbecile/fa/state"
+require_relative "imbecile/fa/state/transition"
 require_relative "imbecile/generator"
 require_relative "imbecile/grammar"
 require_relative "imbecile/grammar/rule"
 require_relative "imbecile/grammar/token"
+require_relative "imbecile/lexer_dfa"
 require_relative "imbecile/regex"
-require_relative "imbecile/regex/fa"
-require_relative "imbecile/regex/fa/state"
-require_relative "imbecile/regex/fa/state/transition"
 require_relative "imbecile/regex/nfa"
 require_relative "imbecile/regex/unit"
-require_relative "imbecile/lexer_dfa"
 require_relative "imbecile/version"
 
 module Imbecile
diff --git a/lib/imbecile/fa.rb b/lib/imbecile/fa.rb
new file mode 100644
index 0000000..489afa7
--- /dev/null
+++ b/lib/imbecile/fa.rb
@@ -0,0 +1,90 @@
+module Imbecile
+
+  class FA
+
+    attr_reader :start_state
+
+    def initialize
+      @start_state = State.new
+    end
+
+    def to_s
+      chr = lambda do |value|
+        if value < 32 || value > 127
+          "{#{value}}"
+        else
+          value.chr
+        end
+      end
+      rv = ""
+      states = enumerate
+      states.each do |state, id|
+        accepts_s = state.accepts ? " #{state.accepts}" : ""
+        rv += "#{id}#{accepts_s}:\n"
+        state.transitions.each do |transition|
+          if transition.nil?
+            range_s = "nil"
+          else
+            range_s = chr[transition.code_point_range.first]
+            if transition.code_point_range.size > 1
+              range_s += "-" + chr[transition.code_point_range.last]
+            end
+          end
+          accepts_s = transition.destination.accepts ? " #{transition.destination.accepts}" : ""
+          rv += "  #{range_s} => #{states[transition.destination]}#{accepts_s}\n"
+        end
+      end
+      rv
+    end
+
+    def enumerate
+      @_enumerated ||=
+        begin
+          id = 0
+          states = {}
+          visit = lambda do |state|
+            unless states.include?(state)
+              states[state] = id
+              id += 1
+              state.transitions.each do |transition|
+                visit[transition.destination]
+              end
+            end
+          end
+          visit[@start_state]
+          states
+        end
+    end
+
+    def build_tables
+      transition_table = []
+      state_table = []
+      states = enumerate
+      states.each do |state, id|
+        accepts =
+          if state.accepts.nil?
+            TOKEN_NONE
+          elsif state.accepts.name
+            state.accepts.id
+          else
+            TOKEN_DROP
+          end
+        state_table << {
+          transition_table_index: transition_table.size,
+          n_transitions: state.transitions.size,
+          accepts: accepts,
+        }
+        state.transitions.each do |transition|
+          transition_table << {
+            first: transition.code_point_range.first,
+            last: transition.code_point_range.last,
+            destination: states[transition.destination],
+          }
+        end
+      end
+      [transition_table, state_table]
+    end
+
+  end
+
+end
diff --git a/lib/imbecile/fa/state.rb b/lib/imbecile/fa/state.rb
new file mode 100644
index 0000000..1373cbc
--- /dev/null
+++ b/lib/imbecile/fa/state.rb
@@ -0,0 +1,51 @@
+module Imbecile
+  class FA
+
+    class State
+
+      attr_accessor :accepts
+      attr_reader :transitions
+
+      def initialize
+        @transitions = []
+      end
+
+      def add_transition(code_point_range, destination)
+        @transitions << Transition.new(code_point_range, destination)
+      end
+
+      # Determine the set of states that can be reached by nil transitions.
+      # from this state.
+      #
+      # @return [Set<NFA::State>]
+      #   Set of states.
+      def nil_transition_states
+        states = Set[self]
+        analyze_state = lambda do |state|
+          state.nil_transitions.each do |transition|
+            unless states.include?(transition.destination)
+              states << transition.destination
+              analyze_state[transition.destination]
+            end
+          end
+        end
+        analyze_state[self]
+        states
+      end
+
+      def nil_transitions
+        @transitions.select do |transition|
+          transition.nil?
+        end
+      end
+
+      def cp_transitions
+        @transitions.reject do |transition|
+          transition.nil?
+        end
+      end
+
+    end
+
+  end
+end
diff --git a/lib/imbecile/fa/state/transition.rb b/lib/imbecile/fa/state/transition.rb
new file mode 100644
index 0000000..bd07671
--- /dev/null
+++ b/lib/imbecile/fa/state/transition.rb
@@ -0,0 +1,23 @@
+module Imbecile
+  class FA
+    class State
+
+      class Transition
+
+        attr_reader :code_point_range
+        attr_reader :destination
+
+        def initialize(code_point_range, destination)
+          @code_point_range = code_point_range
+          @destination = destination
+        end
+
+        def nil?
+          @code_point_range.nil?
+        end
+
+      end
+
+    end
+  end
+end
diff --git a/lib/imbecile/lexer_dfa.rb b/lib/imbecile/lexer_dfa.rb
index 8ec7965..63570d8 100644
--- a/lib/imbecile/lexer_dfa.rb
+++ b/lib/imbecile/lexer_dfa.rb
@@ -1,6 +1,6 @@
 module Imbecile
 
-  class LexerDFA < Regex::FA
+  class LexerDFA < FA
 
     def initialize(tokens)
       super()
diff --git a/lib/imbecile/regex/fa.rb b/lib/imbecile/regex/fa.rb
deleted file mode 100644
index 076d715..0000000
--- a/lib/imbecile/regex/fa.rb
+++ /dev/null
@@ -1,92 +0,0 @@
-module Imbecile
-  class Regex
-
-    class FA
-
-      attr_reader :start_state
-
-      def initialize
-        @start_state = State.new
-      end
-
-      def to_s
-        chr = lambda do |value|
-          if value < 32 || value > 127
-            "{#{value}}"
-          else
-            value.chr
-          end
-        end
-        rv = ""
-        states = enumerate
-        states.each do |state, id|
-          accepts_s = state.accepts ? " #{state.accepts}" : ""
-          rv += "#{id}#{accepts_s}:\n"
-          state.transitions.each do |transition|
-            if transition.nil?
-              range_s = "nil"
-            else
-              range_s = chr[transition.code_point_range.first]
-              if transition.code_point_range.size > 1
-                range_s += "-" + chr[transition.code_point_range.last]
-              end
-            end
-            accepts_s = transition.destination.accepts ? " #{transition.destination.accepts}" : ""
-            rv += "  #{range_s} => #{states[transition.destination]}#{accepts_s}\n"
-          end
-        end
-        rv
-      end
-
-      def enumerate
-        @_enumerated ||=
-          begin
-            id = 0
-            states = {}
-            visit = lambda do |state|
-              unless states.include?(state)
-                states[state] = id
-                id += 1
-                state.transitions.each do |transition|
-                  visit[transition.destination]
-                end
-              end
-            end
-            visit[@start_state]
-            states
-          end
-      end
-
-      def build_tables
-        transition_table = []
-        state_table = []
-        states = enumerate
-        states.each do |state, id|
-          accepts =
-            if state.accepts.nil?
-              TOKEN_NONE
-            elsif state.accepts.name
-              state.accepts.id
-            else
-              TOKEN_DROP
-            end
-          state_table << {
-            transition_table_index: transition_table.size,
-            n_transitions: state.transitions.size,
-            accepts: accepts,
-          }
-          state.transitions.each do |transition|
-            transition_table << {
-              first: transition.code_point_range.first,
-              last: transition.code_point_range.last,
-              destination: states[transition.destination],
-            }
-          end
-        end
-        [transition_table, state_table]
-      end
-
-    end
-
-  end
-end
diff --git a/lib/imbecile/regex/fa/state.rb b/lib/imbecile/regex/fa/state.rb
deleted file mode 100644
index ee4fab9..0000000
--- a/lib/imbecile/regex/fa/state.rb
+++ /dev/null
@@ -1,53 +0,0 @@
-module Imbecile
-  class Regex
-    class FA
-
-      class State
-
-        attr_accessor :accepts
-        attr_reader :transitions
-
-        def initialize
-          @transitions = []
-        end
-
-        def add_transition(code_point_range, destination)
-          @transitions << Transition.new(code_point_range, destination)
-        end
-
-        # Determine the set of states that can be reached by nil transitions.
-        # from this state.
-        #
-        # @return [Set<NFA::State>]
-        #   Set of states.
-        def nil_transition_states
-          states = Set[self]
-          analyze_state = lambda do |state|
-            state.nil_transitions.each do |transition|
-              unless states.include?(transition.destination)
-                states << transition.destination
-                analyze_state[transition.destination]
-              end
-            end
-          end
-          analyze_state[self]
-          states
-        end
-
-        def nil_transitions
-          @transitions.select do |transition|
-            transition.nil?
-          end
-        end
-
-        def cp_transitions
-          @transitions.reject do |transition|
-            transition.nil?
-          end
-        end
-
-      end
-
-    end
-  end
-end
diff --git a/lib/imbecile/regex/fa/state/transition.rb b/lib/imbecile/regex/fa/state/transition.rb
deleted file mode 100644
index 5bd0efb..0000000
--- a/lib/imbecile/regex/fa/state/transition.rb
+++ /dev/null
@@ -1,25 +0,0 @@
-module Imbecile
-  class Regex
-    class FA
-      class State
-
-        class Transition
-
-          attr_reader :code_point_range
-          attr_reader :destination
-
-          def initialize(code_point_range, destination)
-            @code_point_range = code_point_range
-            @destination = destination
-          end
-
-          def nil?
-            @code_point_range.nil?
-          end
-
-        end
-
-      end
-    end
-  end
-end