Fix sqrt type inference and add regression coverage

lynglib/src/commonTest/kotlin/LocalRealMemberInferenceRegressionTest.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+import kotlinx.coroutines.test.runTest
+import net.sergeych.lyng.eval
+import net.sergeych.lyng.obj.ObjBool
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class LocalRealMemberInferenceRegressionTest {
+
+    @Test
+    fun sqrtInitializedLocalVarKeepsRealReceiverTypeForMembers() = runTest {
+        val result = eval(
+            """
+            fun probe(T: Real, c: Real, g: Real): Bool {
+                fun passthrough(h: Real): Real = h / c
+
+                val term = 1.0 + g * T / c
+                val sqrtTerm = sqrt(1.0 + 2.0 * g * T / c)
+                assert(sqrtTerm is Real)
+                assert(!sqrtTerm.isNaN())
+                var h = (c * c / g) * (term - sqrtTerm)
+                assert(passthrough(h) >= 0.0)
+                assert(h is Real)
+                !h.isNaN()
+            }
+
+            probe(6.0, 340.0, 9.81)
+            """.trimIndent()
+        )
+
+        assertEquals(ObjBool(true), result)
+    }
+}

lynglib/src/commonTest/kotlin/ScriptTest.kt

@@ -5576,7 +5576,7 @@ class ScriptTest {
             
             val depth = calculateDepth(T, m, d)
             if (depth != null) {
-                println("Глубина: %.2f м".format(depth))
+                println("Глубина: %.2f м"(depth))
             } else {
                 println("Расчёт не сошёлся")
             }