diff --git a/prototype/Doubt.xcodeproj/project.pbxproj b/prototype/Doubt.xcodeproj/project.pbxproj
index e104eed43..699ff4b0e 100644
--- a/prototype/Doubt.xcodeproj/project.pbxproj
+++ b/prototype/Doubt.xcodeproj/project.pbxproj
@@ -24,7 +24,7 @@
 		D432D4711BA9AC0B00F3FABC /* SESTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D432D4701BA9AC0B00F3FABC /* SESTests.swift */; };
 		D4413FEF1BB06D4C00E3C3C1 /* Dictionary.swift in Sources */ = {isa = PBXBuildFile; fileRef = D4413FEE1BB06D4C00E3C3C1 /* Dictionary.swift */; };
 		D4413FF11BB08FDC00E3C3C1 /* JSON.swift in Sources */ = {isa = PBXBuildFile; fileRef = D4413FF01BB08FDC00E3C3C1 /* JSON.swift */; };
-		D45A36C91BBC667D00BE3DDE /* Category.swift in Sources */ = {isa = PBXBuildFile; fileRef = D45A36C81BBC667D00BE3DDE /* Category.swift */; settings = {ASSET_TAGS = (); }; };
+		D45A36C91BBC667D00BE3DDE /* Categorizable.swift in Sources */ = {isa = PBXBuildFile; fileRef = D45A36C81BBC667D00BE3DDE /* Categorizable.swift */; settings = {ASSET_TAGS = (); }; };
 		D45A36CD1BBC75DF00BE3DDE /* Info.swift in Sources */ = {isa = PBXBuildFile; fileRef = D45A36CC1BBC75DF00BE3DDE /* Info.swift */; settings = {ASSET_TAGS = (); }; };
 		D49FCBC21BBEF2C600C5E9C3 /* Fix.swift in Sources */ = {isa = PBXBuildFile; fileRef = D49FCBC11BBEF2C600C5E9C3 /* Fix.swift */; settings = {ASSET_TAGS = (); }; };
 		D49FCBC41BBEF98E00C5E9C3 /* Free.swift in Sources */ = {isa = PBXBuildFile; fileRef = D49FCBC31BBEF98E00C5E9C3 /* Free.swift */; settings = {ASSET_TAGS = (); }; };
@@ -66,7 +66,7 @@
 		D435B7521BB31BBC000902F6 /* BoundsCheckedArray.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BoundsCheckedArray.swift; sourceTree = "<group>"; };
 		D4413FEE1BB06D4C00E3C3C1 /* Dictionary.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Dictionary.swift; sourceTree = "<group>"; };
 		D4413FF01BB08FDC00E3C3C1 /* JSON.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = JSON.swift; sourceTree = "<group>"; };
-		D45A36C81BBC667D00BE3DDE /* Category.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Category.swift; sourceTree = "<group>"; };
+		D45A36C81BBC667D00BE3DDE /* Categorizable.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Categorizable.swift; sourceTree = "<group>"; };
 		D45A36CC1BBC75DF00BE3DDE /* Info.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Info.swift; sourceTree = "<group>"; };
 		D49FCBC11BBEF2C600C5E9C3 /* Fix.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Fix.swift; sourceTree = "<group>"; };
 		D49FCBC31BBEF98E00C5E9C3 /* Free.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Free.swift; sourceTree = "<group>"; };
@@ -163,7 +163,7 @@
 				D4413FF01BB08FDC00E3C3C1 /* JSON.swift */,
 				D40B89C31BC319070078E098 /* Matrix.swift */,
 				D4D7F3161BBB22E500AAB0C0 /* Hash.swift */,
-				D45A36C81BBC667D00BE3DDE /* Category.swift */,
+				D45A36C81BBC667D00BE3DDE /* Categorizable.swift */,
 				D45A36CC1BBC75DF00BE3DDE /* Info.swift */,
 				D49FCBC11BBEF2C600C5E9C3 /* Fix.swift */,
 				D49FCBC31BBEF98E00C5E9C3 /* Free.swift */,
@@ -347,7 +347,7 @@
 				D4AAE5471B5AE2D0004E581F /* Optional.swift in Sources */,
 				D4413FEF1BB06D4C00E3C3C1 /* Dictionary.swift in Sources */,
 				D4D7F3171BBB22E500AAB0C0 /* Hash.swift in Sources */,
-				D45A36C91BBC667D00BE3DDE /* Category.swift in Sources */,
+				D45A36C91BBC667D00BE3DDE /* Categorizable.swift in Sources */,
 				D4DF96ED1BC46B630040F41F /* SES.swift in Sources */,
 				D4AAE5401B5AE2D0004E581F /* RangeReplaceableCollectionType.swift in Sources */,
 				D49FCBC21BBEF2C600C5E9C3 /* Fix.swift in Sources */,
diff --git a/prototype/Doubt/Category.swift b/prototype/Doubt/Categorizable.swift
similarity index 100%
rename from prototype/Doubt/Category.swift
rename to prototype/Doubt/Categorizable.swift