add quotient circuit structure and improve fmt for polynomials

examples/quotient.rs

@@ -0,0 +1,21 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
+use circuit_cas::circuit::quotient::Quotient;
+use circuit_cas::poly::var::StaticVar;
+use circuit_cas::var;
+
+fn main() {
+    let x=var!("x");
+    let nx=var!("x\u{0304}");
+
+    let idem = vec![
+        1*(&x^2)-1*(&x^1),
+        1*(&nx^2)-1*(&nx^1),
+        1*((&x^1)*(&nx^1))-1*(&x^1),
+    ];
+
+    let mut quotient:Quotient<StaticVar>=idem.into_iter().collect();
+
+    println!("{quotient}");
+}