Configuration (Turing Machine)

computation

Definition

Configuration (Turing Machine)

A configuration is a complete snapshot of a Turing machine at a single moment.

Move to left, i.e.: $\delta (q,X_i)=(p,Y,\underline{L})$:

$$X_1{X}_2\dots X_{i-1}q{X}_i{X}_{i+1}\dots X_n⟹X_1{X}_2\dots X_{i-2}p{X}_{i-1}Y{X}_{i+1}\dots X_n$$

Move to right, i.e.: $\delta (q,X_i)=(p,Y,\underline{R})$:

$$X_1{X}_2\dots X_{i-1}q{X}_i{X}_{i+1}\dots X_n⟹X_1{X}_2\dots X_{i-1}Yp{X}_{i+1}{X}_{i+2}\dots X_n$$

Move stays (no movement), i.e.: $\delta (q,X_i)=(p,Y,\underline{S})$:

$$X_1{X}_2\dots X_{i-1}q{X}_i{X}_{i+1}\dots X_n⟹X_1{X}_2\dots X_{i-1}pY{X}_{i+1}\dots X_n$$