diff --git a/TODO.md b/TODO.md
index 7240b1a2..bdf65cb6 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,4 +1,14 @@
-`interact` -- be sure about memeory leak of `connection`
+drop the `net` prefix for `graph/` functions
+
+use unicode for subscript number
+
+rename PortConnect to PortReconnect
+
+`connect` v.s. `reconnect`
+
+- `reconnect` is used in `PortReconnect`
+
+`interact` -- be sure about memeory leak from `port.connection`
 
 # bug
 
diff --git a/src/lang/graph/findPortInActiveEdge.ts b/src/lang/graph/findPortInActiveEdge.ts
new file mode 100644
index 00000000..71f28daa
--- /dev/null
+++ b/src/lang/graph/findPortInActiveEdge.ts
@@ -0,0 +1,29 @@
+import { ActiveEdge, Node, Port } from "../graph"
+
+export function findPortInActiveEdge(
+  nodeName: string,
+  portName: string,
+  activeEdge: ActiveEdge,
+): Port | undefined {
+  if (nodeName === activeEdge.start.node.name) {
+    return findPortInNode(portName, activeEdge.start.node)
+  }
+
+  if (nodeName === activeEdge.end.node.name) {
+    return findPortInNode(portName, activeEdge.end.node)
+  }
+}
+
+function findPortInNode(portName: string, node: Node): Port | undefined {
+  for (const port of node.input) {
+    if (port.name === portName) {
+      return port.connection?.port
+    }
+  }
+
+  for (const port of node.output) {
+    if (port.name === portName) {
+      return port.connection?.port
+    }
+  }
+}
diff --git a/src/lang/words/PortConnect.ts b/src/lang/words/PortConnect.ts
index 2f301b8f..3a60e885 100644
--- a/src/lang/words/PortConnect.ts
+++ b/src/lang/words/PortConnect.ts
@@ -1,9 +1,9 @@
 import { Net } from "../graph"
+import { findPortInActiveEdge } from "../graph/findPortInActiveEdge"
 import { netConnectPorts } from "../graph/netConnectPorts"
 import { Mod } from "../mod"
 import { Span } from "../span"
 import { Word, WordOptions } from "../word"
-import { findPortInActiveEdge } from "./PortPush"
 
 export class PortConnect implements Word {
   constructor(
diff --git a/src/lang/words/PortPush.ts b/src/lang/words/PortPush.ts
index 2756d4d9..1a0e9830 100644
--- a/src/lang/words/PortPush.ts
+++ b/src/lang/words/PortPush.ts
@@ -1,4 +1,5 @@
-import { ActiveEdge, Net, Node, Port } from "../graph"
+import { Net } from "../graph"
+import { findPortInActiveEdge } from "../graph/findPortInActiveEdge"
 import { Mod } from "../mod"
 import { Span } from "../span"
 import { Word, WordOptions } from "../word"
@@ -28,31 +29,3 @@ export class PortPush implements Word {
     net.portStack.push(found)
   }
 }
-
-export function findPortInActiveEdge(
-  nodeName: string,
-  portName: string,
-  activeEdge: ActiveEdge,
-): Port | undefined {
-  if (nodeName === activeEdge.start.node.name) {
-    return findPortInNode(portName, activeEdge.start.node)
-  }
-
-  if (nodeName === activeEdge.end.node.name) {
-    return findPortInNode(portName, activeEdge.end.node)
-  }
-}
-
-function findPortInNode(portName: string, node: Node): Port | undefined {
-  for (const port of node.input) {
-    if (port.name === portName) {
-      return port.connection?.port
-    }
-  }
-
-  for (const port of node.output) {
-    if (port.name === portName) {
-      return port.connection?.port
-    }
-  }
-}