inorder ( call inorder ( visit call inorder (cfigure inorder (binorder ( call inorder (null visit call inorder (null call inorder (null visit call inorder (nullinorder (nullinorder (nullinorder (nullinorder (nullreturns returns returns returns the inorder(method applied to three-node tree we start by calling inorder(with the root as an argument this incarnation of inorder(we'll call inorder(ainorder(afirst calls inorder(with its left childbas an argument this second incarnation of inorder(we'll call inorder(binorder(bnow calls itself with its left child as an argument howeverit has no left childso this argument is null this creates an invocation of inorder(we could call inorder(nullthere are now three instances of inorder(in existenceinorder( )inorder( )and inorder(nullhoweverinorder(nullreturns immediately when it finds its argument is null (we all have days like that now inorder(bgoes on to visit bwe'll assume this means to display it then inorder(bcalls inorder(againwith its right child as an argument again this argument is nullso the second inorder(nullreturns immediately now inorder(bhas carried out steps and so it returns (and thereby ceases to exist