[Grammar] You should know better than to behave like that

[kadioguy]

In the OALD, it writes:

than
preposition, conjunction

You should know better than to behave like that.
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Which one does it mean?
1. 'You should know better than (You should) to behave like that.'?
2. 'You should know better than (You know) to behave like that.'?
3. 'You should know better than (You should know) to behave like that.'?
4. 'You should know better than (You) to behave like that.'?
5. 'You should know better than (You are going) to behave like that.'?
6. 'You should know better than You behave like that.'?
7. other answers


Why not 'You should know better than behave like that.'? (no 'to')

 

[Tdol]

7 It means that the person behaved badly or incorrectly, when they should know/should have known better.

 

[kadioguy]

For example, 'I'm older than her.' means 'I'm older than she (is old)'.

So how can I use the pattern in 'You should know better than to behave like that'?