a field-theory motivated approach to computer algebra


Eliminate Kronecker delta symbols.
Eliminates Kronecker delta symbols by performing index contractions. Also replaces contracted Kronecker delta symbols with the range over which the index runs, if known.
\delta_{m n}::KroneckerDelta. ex:=A_{m p} \delta_{p q} B_{q n}; eliminate_kronecker(_);
\(\displaystyle{}A_{m p} \delta_{p q} B_{q n}\)
\(\displaystyle{}A_{m q} B_{q n}\)
The index range is set as usual with Integer,
{m,n,p,q}::Integer(0..d-1). \delta_{m n}::KroneckerDelta. ex:=\delta_{p q} \delta_{p q}; eliminate_kronecker(_);
\(\displaystyle{}\delta_{p q} \delta_{p q}\)
In order to eliminate metric factors (i.e. to 'raise' and 'lower' indices) use the algorithm eliminate_metric.
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