> [!example] Example of a syntactic tree
> ```mermaid
>graph TD
> root(S)
> rootPP(PP)
> rootNP(NP)
> rootVP(VP)
> root --> rootPP
> root --> rootNP
> root --> rootVP
>
> rootPPIN(IN)
> rootPPNP(NP)
> rootPP --> rootPPIN
> rootPP --> rootPPNP
> rootPPIN --> rootPPINin(in)
>
> rootPPNPPRP$(PRP$)
> rootPPNPJJ(JJ)
> rootPPNPNNS(NNS)
> rootPPNP --> rootPPNPPRP$
> rootPPNP --> rootPPNPJJ
> rootPPNP --> rootPPNPNNS
> rootPPNPPRP$ --> rootPPNPPRP$their(their)
> rootPPNPJJ --> rootPPNPJJpublic(public)
> rootPPNPNNS --> rootPPNPNNSlectures(lectures)
>
> rootNP --> rootNPPRP(PRP)
> rootNPPRP --> rootNPPRPthey(they)
>
> rootVP --> rootVPVBP(VBP)
> rootVP --> rootVPRB(RB)
> rootVP --> rootVPVP(VP)
> rootVPVBP --> rootVPVBPhave(have)
> rootVPRB --> rootVPRBeven(even)
>
> rootVPVP --> rootVPVPVBN(VBN)
> rootVPVPVBN --> rootVPVPVBNclaimed(claimed)
> rootVPVP --> rootVPVPSBAR(SBAR)
> rootVPVPSBAR --> rootVPVPSBARIN(IN)
> rootVPVPSBAR --> rootVPVPSBARS(S)
> rootVPVPSBARIN --> rootVPVPSBARINthat(that)
>
> rootVPVPSBARS --> rootVPVPSBARSdots(...)
> ```
**What does a syntactic tree consist of?**
A syntactic tree consists of *a set of vertices branching down from a root vertex.*
> **What does each vertex in a syntactic tree have?**
> Each vertex in a syntactic tree has *a label and an ordered sequence of children.*
>
> **What are vertices with no children called?**
> Vertices with no children are called *terminal nodes.*
> > **What are vertices that come just before terminal nodes called?**
> > Vertices that come just before terminal nodes are called *pre-terminal nodes.*
>
> **What do pre-terminal labels correspond to?**
> Pre-terminal labels correspond to *parts of speech of traditional grammar.*
...