diff --git a/src/main/kotlin/com/github/insanusmokrassar/PsychomatrixBase/domain/entities/operations/Operation.kt b/src/main/kotlin/com/github/insanusmokrassar/PsychomatrixBase/domain/entities/operations/Operation.kt
index 942645e..970e7d1 100644
--- a/src/main/kotlin/com/github/insanusmokrassar/PsychomatrixBase/domain/entities/operations/Operation.kt
+++ b/src/main/kotlin/com/github/insanusmokrassar/PsychomatrixBase/domain/entities/operations/Operation.kt
@@ -1,7 +1,5 @@
 package com.github.insanusmokrassar.PsychomatrixBase.domain.entities.operations
 
-import java.io.IOException
-
 private const val oneAsByte: Byte = 1
 private const val twoAsByte: Byte = 2
 private const val fourAsByte: Byte = 4
@@ -11,8 +9,6 @@ private const val sevenAsByte: Byte = 7
 private const val eightAsByte: Byte = 8
 private const val nineAsByte: Byte = 9
 
-class ConverterException: IOException("This converter can't convert input numbers")
-
 val List<Operation>.canGrowSimpleWay: Boolean
     get() = contains(SixGrowSeven)
 
@@ -33,12 +29,12 @@ private val operations: List<Operation> = listOf(
     }.toTypedArray()
 )
 
-suspend fun availableConverts(numbers: MutableList<Byte>, operations: List<Operation>): List<Operation> {
-    return operations.filter { it.canConvert(numbers, operations) }
+suspend fun availableConverts(numbers: MutableList<Byte>, history: List<Operation>): List<Operation> {
+    return operations.filter { it.canConvert(numbers, history) }
 }
 
-suspend fun availableInverts(numbers: MutableList<Byte>, operations: List<Operation>): List<Operation> {
-    return operations.filter { it.canInvert(numbers, operations) }
+suspend fun availableInverts(numbers: MutableList<Byte>, history: List<Operation>): List<Operation> {
+    return operations.filter { it.canInvert(numbers, history) }
 }
 
 sealed class Operation {