fix docstring

Author: vyudu

src/systems/abstractsystem.jl

@@ -718,14 +718,14 @@ function add_initialization_parameters(sys::AbstractSystem)
 end
 
 """
-Returns true if the variable or parameter `var` is of the form `Initial(x)`.
-"""
-function isInitial(var)
-    var = unwrap(var)
-    if iscall(var)
-        operation(var) isa Initial && return true
-        if operation(var) === getindex
-            operation(arguments(var)[1]) isa Initial && return true
+Returns true if the parameter `p` is of the form `Initial(x)`.
+"""
+function isInitial(p)
+    p = unwrap(p)
+    if iscall(p)
+        operation(p) isa Initial && return true
+        if operation(p) === getindex
+            operation(arguments(p)[1]) isa Initial && return true
         end
     else
         return false