!!

(!!) repeats the previous entered expression by re-evaluating it in interactive mode of Inlab Scheme and returns the result of this evaluation.

(!! <expression-no>) repeats the previous entered expression with the given expression number by reevaluating it and returns the result of the evaluation.

Example:

[1] (define a 1)
a
[2] (set! a (+ a 1))
a
[3] (!!)
a
[4] a
3
[5]