--- a/src/th06/std_vm.rs
+++ b/src/th06/std_vm.rs
@@ -1,8 +1,8 @@
 //! Interpreter of STD files.
 
-use crate::th06::std::{Stage, Position, Call, Instruction};
-use crate::th06::interpolator::{Interpolator1, Interpolator3, Interpolator4, Formula};
-use crate::util::math::{Mat4, perspective, setup_camera};
+use crate::th06::std::{Stage, Call, Instruction};
+use crate::th06::interpolator::{Interpolator3, Formula};
+use crate::util::math::{Mat4, setup_camera};
 use std::cell::RefCell;
 use std::rc::Rc;