GraphComplement[g] gives the complement of graph g.
CircleMinus[x, y] displays as x\[CircleMinus]y.
EmptyGraphQ[g] yields True if g is an empty graph and False otherwise.
SelfComplementaryQ[g] yields True if graph g is self-complementary, meaning it is isomorphic to its complement.
GraphUnion[g_1, g_2] gives the graph union of the graphs g_1 and g_2.GraphUnion[g_1, g_2, ...] gives the graph union of g_1, g_2, ....
IndependentVertexSetQ[g, vlist] yields True if the vertex list vlist is an independent vertex set in the graph g and False otherwise.
ClearAttributes[s, attr] removes attr from the list of attributes of the symbol s.
SystemsModelDelete[sys, {i_1, i_2, ...}] deletes the subsystem of the StateSpaceModel or TransferFunctionModel object sys associated with inputs at position ...
Union
(Built-in Mathematica Symbol) Union[list_1, list_2, ...] gives a sorted list of all the distinct elements that appear in any of the list_i. Union[list] gives a sorted version of a list, in which all ...
Take
(Built-in Mathematica Symbol) Take[list, n] gives the first n elements of list. Take[list, -n] gives the last n elements of list. Take[list, {m, n}] gives elements m through n of list. Take[list, seq_1, ...