Sn = symmetric group For each p in Sn associate a +1(p even) or -1(p odd) a group algebra can be defined on the elements of Sn. Theorem: The number of standard young tableau corresponding to a particular young diagram = dim of associated irrep denoted by the diagram. Sn has the general symmetry elements built from the symmetrizer, antisymmetrizer, and young diagrams. Define a general symmetry as: Yl,q=Sl,q*Al,q where l = the particular young diagram, q= the particular numbering of the young diagram, Sl,q= symmetry on the rows, and Al,q=antisymmetry on the columns. Example: 1 2 3 =(e+12)(e-13) 12 34 = (e+(12))(e+(34))(e-(13))(e-(24))