Clean up example a bit

Author: hersle

docs/src/tutorials/nonlinear.md

@@ -9,31 +9,26 @@ We use (unknown) variables for our nonlinear system.
 ```@example nonlinear
 using ModelingToolkit, NonlinearSolve
 
+# Define a nonlinear system
 @variables x y z
 @parameters σ ρ β
+@mtkbuild ns = NonlinearSystem([
+    0 ~ σ * (y - x)
+    0 ~ x * (ρ - z) - y
+    0 ~ x * y - β * z
+])
 
-# Define a nonlinear system
-eqs = [0 ~ σ * (y - x),
-    0 ~ x * (ρ - z) - y,
-    0 ~ x * y - β * z]
-@mtkbuild ns = NonlinearSystem(eqs, [x, y, z], [σ, ρ, β])
-
-guess = [x => 1.0,
-    y => 0.0,
-    z => 0.0]
-
-ps = [σ => 10.0
-      ρ => 26.0
-      β => 8 / 3]
+guesses = [x => 1.0, y => 0.0, z => 0.0]
+ps = [σ => 10.0, ρ => 26.0, β => 8 / 3]
 
-prob = NonlinearProblem(ns, guess, ps)
+prob = NonlinearProblem(ns, guesses, ps)
 sol = solve(prob, NewtonRaphson())
 ```
 
 We can similarly ask to generate the `NonlinearProblem` with the analytical
 Jacobian function:
 
 ```@example nonlinear
-prob = NonlinearProblem(ns, guess, ps, jac = true)
+prob = NonlinearProblem(ns, guesses, ps, jac = true)
 sol = solve(prob, NewtonRaphson())
 ```