Simple infinite recursion:
<b>[Error: Too deep recursion: RTAG -> RTAG -> RTAG -> RTAG -> RTAG -> RTAG -> RTAG -> RTAG -> RTAG -> RTAG -> RTAG]</b>

Complex infinite recursion:
<b>[Error: Too deep recursion: 1TAG -> 2TAG -> REDTAG -> BLUETAG -> 1TAG -> 2TAG -> REDTAG -> BLUETAG -> 1TAG -> 2TAG -> REDTAG]</b>