diff --git a/src/commonMain/kotlin/ai/hypergraph/kaliningraph/parsing/SeqValiant.kt b/src/commonMain/kotlin/ai/hypergraph/kaliningraph/parsing/SeqValiant.kt
index 5e2f4a4b..8ee91209 100644
--- a/src/commonMain/kotlin/ai/hypergraph/kaliningraph/parsing/SeqValiant.kt
+++ b/src/commonMain/kotlin/ai/hypergraph/kaliningraph/parsing/SeqValiant.kt
@@ -3,14 +3,13 @@ package ai.hypergraph.kaliningraph.parsing
 import ai.hypergraph.kaliningraph.tensor.UTMatrix
 import ai.hypergraph.kaliningraph.types.*
 
-typealias PForest = Set<PTree>
-operator fun PForest.contains(v: Σᐩ) = PTree(v) in this
-fun PSingleton(v: Σᐩ): List<Π2A<PTree>> = listOf(PTree(v) to PTree())
+typealias PForest = Map<String, PTree>
+fun PSingleton(v: String): List<Π2A<PTree>> = listOf(PTree(v) to PTree())
 
 // Algebraic data type / polynomial functor for parse forests
-class PTree(val root: Σᐩ = "ε", val branches: List<Π2A<PTree>> = listOf()) {
+class PTree(val root: String = "ε", val branches: List<Π2A<PTree>> = listOf()) {
   // Returns the set of all strings derivable from the given PTree
-  fun choose(): Sequence<Σᐩ> =
+  fun choose(): Sequence<String> =
     if (branches.isEmpty()) sequenceOf(if("ε" in root) "" else root)
     else branches.asSequence().flatMap { (l, r) ->
       // TODO: Use weighted choice mechanism
@@ -18,44 +17,38 @@ class PTree(val root: Σᐩ = "ε", val branches: List<Π2A<PTree>> = listOf())
         if (a == "") b else if (b == "") a else "$a $b"
       }
     }
-
-  override fun hashCode(): Int = root.hashCode()
-  override fun equals(other: Any?) = hashCode() == other.hashCode()
 }
 
 // Lazily computes all syntactically strings compatible with the given template
-fun CFG.solveSeq(s: Σᐩ): Sequence<Σᐩ> =
-  initPForestMat(s.tokenizeByWhitespace()).seekFixpoint().diagonals.last()[0]
-    .firstOrNull { it.root == START_SYMBOL }?.choose() ?: emptySequence()
+fun CFG.solveSeq(s: String): Sequence<String> =
+    initPForestMat(s.tokenizeByWhitespace()).seekFixpoint()
+      .diagonals.last()[0][START_SYMBOL]?.choose() ?: emptySequence()
 
-fun CFG.initPForestMat(tokens: List<Σᐩ>): UTMatrix<PForest> =
+fun CFG.initPForestMat(tokens: List<String>): UTMatrix<PForest> =
   UTMatrix(
     ts = tokens.map { token ->
       (if (token != HOLE_MARKER) bimap[listOf(token)] else unitNonterminals)
         .associateWith { nt ->
           if (token != HOLE_MARKER) PSingleton(token)
           else bimap.UNITS[nt]?.map { PSingleton(it) }?.flatten() ?: listOf()
-        }.map { (k, v) -> PTree(k, v) }.toSet()
+        }.map { (k, v) -> k to PTree(k, v) }.toMap()
     }.toTypedArray(),
     algebra = Ring.of(
-      nil = emptySet(),
+      nil = emptyMap(),
       plus = { x, y -> merge(x, y) },
       times = { x, y -> joinSeq(x, y) },
     )
   )
 
 fun merge(X: PForest, Z: PForest): PForest =
-  (X.toList() + Z).groupBy { it.root }.map { (k, v) ->
-    PTree(k, v.map { it.branches }.flatten())
-  }.toSet()
+  (X.keys + Z.keys).associateWith { k ->
+    PTree(k, (X[k]?.branches ?: listOf()) + (Z[k]?.branches ?: listOf()))
+  }
 
 // X ⊗ Z := { w | <x, z> ∈ X × Z, (w -> xz) ∈ P }
 fun CFG.joinSeq(X: PForest, Z: PForest): PForest =
   bimap.TRIPL.filter { (_, x, z) -> x in X && z in Z }
-    .groupingBy { it.first }.aggregate { _, acc: List<Π2A<PTree>>?, it, _-> 
-      val (w, x, z) = it
-      val ptreeX = X.first { it.root == x }
-      val ptreeZ = Z.first { it.root == z }
-      val pair = ptreeX to ptreeZ
+    .groupingBy { it.first }.aggregate { _, acc: List<Π2A<PTree>>?, it, _->
+      val pair = X[it.second]!! to Z[it.third]!!
       if (acc == null) listOf(pair) else acc + pair
-    }.map { (k, v) -> PTree(k, v) }.toSet()
\ No newline at end of file
+    }.map { (k, v) -> k to PTree(k, v) }.toMap()
\ No newline at end of file
diff --git a/src/commonTest/kotlin/ai/hypergraph/kaliningraph/parsing/SetValiantTest.kt b/src/commonTest/kotlin/ai/hypergraph/kaliningraph/parsing/SetValiantTest.kt
index 0f611f83..6caadc2f 100644
--- a/src/commonTest/kotlin/ai/hypergraph/kaliningraph/parsing/SetValiantTest.kt
+++ b/src/commonTest/kotlin/ai/hypergraph/kaliningraph/parsing/SetValiantTest.kt
@@ -583,8 +583,13 @@ Yield_Arg -> From_Keyword Test | Testlist_Endcomma
     val refLst = refStr.tokenizeByWhitespace()
     val template = List(refLst.size + 3) { "_" }.joinToString(" ")
     measureTime {
-      seq2parsePythonCFG.solve(template, levMetric(refStr))
-        .onEach { println("Δ=${levenshtein(it, refStr)}: $it") }
+//      seq2parsePythonCFG.solve(template, levMetric(refStr))
+      seq2parsePythonCFG.solveSeq(template)
+        .map { it to levenshtein(it, refStr) }
+        .filter { it.second < 4 }.distinct()
+        .sortedWith(compareBy({ it.second }, { it.first.length })).toList()
+        .also { it.take(1000).forEach { println("Δ=${it.second}: ${it.first}") } }
+//        .onEach { println("Δ=${levenshtein(it, refStr)}: $it") }
         .also { println("Found ${it.size} solutions!") }
     }.also { println("Finished in ${it.inWholeMilliseconds}ms.") }
   }