Type BinaryTree
    valor As Integer
    izda As BinaryTree Ptr
    dcha As BinaryTree Ptr
End Type

Sub PrintTree(t As BinaryTree Ptr, depth As Integer)
    If t = 0 Then Exit Sub
    Print String(depth, Chr(9)); t->valor
    PrintTree(t->izda, depth + 1)
    PrintTree(t->dcha, depth + 1)
End Sub

Dim As BinaryTree b = Type(6)
Dim As BinaryTree bLeft = Type(5)
Dim As BinaryTree bRight = Type(7)
b.izda = @bLeft
b.dcha = @bRight

PrintTree(@b, 0)