A Turing Machine with Left Tab L is similar to a normal Turing machine except that its transition function is defined as

: Q x -> Q x x {L, R, T}

where T is an extra tape directive (in addition to L and R) that moves the read/write head to the first blank space to the left of the read/write head. (This does not always mean to the left of where the input string started as a blank can be written at any time during computation.) Show that L is Turing-complete.