diff --git a/src/physics.rs b/src/physics.rs
index 74e9ae5..df68b4f 100644
--- a/src/physics.rs
+++ b/src/physics.rs
@@ -843,7 +843,7 @@ impl Body{
 		self.velocity=self.extrapolated_velocity(time);
 		self.time=time;
 	}
-	pub fn extrapolated_position_ratio_dt<Num,Den,N1,D1,N2,N3,D2,N4,N5,N6,T1>(&self,dt:integer::Ratio<Num,Den>)->Planar64Vec3
+	pub fn extrapolated_position_ratio_dt<Num,Den,N1,D1,N2,N3,D2,N4,T1>(&self,dt:integer::Ratio<Num,Den>)->Planar64Vec3
 		where
 			// Why?
 			// All of this can be removed with const generics because the type can be specified as
@@ -858,29 +858,27 @@ impl Body{
 			Num:core::ops::Mul<N3,Output=N4>,
 			Den:core::ops::Mul<D1,Output=D2>,
 			D2:Copy,
-			Planar64:core::ops::Mul<D2,Output=N5>,
-			N4:core::ops::Add<N5,Output=N6>,
-			N6:integer::Divide<D2,Output=T1>,
+			Planar64:core::ops::Mul<D2,Output=N4>,
+			N4:integer::Divide<D2,Output=T1>,
 			T1:integer::Fix<Planar64>,
 	{
 		// a*dt^2/2 + v*dt + p
 		// (a*dt/2+v)*dt+p
-		((self.acceleration.map(|elem|dt*elem/2)+self.velocity).map(|elem|dt.mul_ratio(elem))+self.position)
-		.map(|elem|elem.divide().fix())
+		(self.acceleration.map(|elem|dt*elem/2)+self.velocity).map(|elem|dt.mul_ratio(elem))
+		.map(|elem|elem.divide().fix())+self.position
 	}
-	pub fn extrapolated_velocity_ratio_dt<Num,Den,N1,N2,N3,T1>(&self,dt:integer::Ratio<Num,Den>)->Planar64Vec3
+	pub fn extrapolated_velocity_ratio_dt<Num,Den,N1,T1>(&self,dt:integer::Ratio<Num,Den>)->Planar64Vec3
 		where
 			Num:Copy,
 			Den:Copy,
 			Num:core::ops::Mul<Planar64,Output=N1>,
-			Planar64:core::ops::Mul<Den,Output=N2>,
-			N1:core::ops::Add<N2,Output=N3>,
-			N3:integer::Divide<Den,Output=T1>,
+			Planar64:core::ops::Mul<Den,Output=N1>,
+			N1:integer::Divide<Den,Output=T1>,
 			T1:integer::Fix<Planar64>,
 	{
 		// a*dt + v
-		(self.acceleration.map(|elem|dt*elem)+self.velocity)
-		.map(|elem|elem.divide().fix())
+		self.acceleration.map(|elem|dt*elem)
+		.map(|elem|elem.divide().fix())+self.velocity
 	}
 	pub fn advance_time_ratio_dt(&mut self,dt:model_physics::GigaTime){
 		self.position=self.extrapolated_position_ratio_dt(dt);