Left Move
Definition: Let c, c’ be two configurations of M. Then,  M makes a left move from c to c’according to r, written as c |–L c’ [r] or, simply, c |–L c’ if
Rule: pa ® qbL
a
x
y
p
Configuration
a
x
y
p
Rule: pa ® qDL
    (1) c = xcpay, c’ = xqcby, y ¹ e or b ¹ D, r:pa |– qbL Î R or
    (2) c = xcpa, c’ = xqc, r: pa |– qDL Î R
c
c
New Configuration
q
b
x
y
q
b
x
y
c
c
…
p
or
a
x
p
Configuration
a
x
c
c
D
D
q
New Configuration
x
q
D
x
c
c
…
D
D
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