Deje que sea un lenguaje regular. Pruebalo:LLL L+−−={w:∃u|u|=2|w|∧wu∈L}L+−−={w:∃u|u|=2|w|∧wu∈L}L_{+--}=\left\{w: \exists_u |u|=2|w| \wedge wu\in L\right\} L++−={w:∃u2|u|=|w|∧wu∈L}L++−={w:∃u2|u|=|w|∧wu∈L}L_{++-}=\left\{w: \exists_u 2|u|=|w| \wedge wu\in L \right\}...