Use this if you are using igraph from R
Difference of vertex sequences
## S3 method for class 'igraph.vs' difference(big, small, ...)
| big | The ‘big’ vertex sequence. | 
| small | The ‘small’ vertex sequence. | 
| ... | Ignored, included for S3 signature compatibility. | 
They must belong to the same graph. Note that this function has ‘set’ semantics and the multiplicity of vertices is lost in the result.
A vertex sequence that contains only vertices that are part of
big, but not part of small.
Other vertex and edge sequence operations: c.igraph.es,
c.igraph.vs,
difference.igraph.es,
igraph-es-indexing2,
igraph-es-indexing,
igraph-vs-indexing2,
igraph-vs-indexing,
intersection.igraph.es,
intersection.igraph.vs,
rev.igraph.es, rev.igraph.vs,
union.igraph.es,
union.igraph.vs,
unique.igraph.es,
unique.igraph.vs
g <- make_(ring(10), with_vertex_(name = LETTERS[1:10])) difference(V(g), V(g)[6:10])