SK Combinator Expression Analysis

Input a valid SK combinator expression or use the random expression above.

Expression:
k[s[k]][k[k[s]][s[s]]][s[s][k[s][s][k[k][s]][s[s[k][k]]][k[k]][s[s][k[s[k]]][s[k][k[s[s][k[k]]][k[s]]]][k[k[s][s[s[k][k]]]]]]]]

Visualisation:
Initial state and first 5 steps of evaluation:
The nth row of the image represents the nth step of evaluation of the combinator.

Graph of Evaluated Expression Lengths:
As the combinator is evaluated, its length changes. This graph plots length of combinator against number of steps of evaluation.

Statistical Analysis of Halting Time:
This combinator has 43 leaves. This combinator falls within the 19th percentile of a random sample of 1000 combinators with leaf size 43, halting after 5 steps - on average, 19.9% of combinators from this sample halt before this one. A graph demonstrating this follows:

Machine Learning Analysis of Halting:
A machine learning model (using logistic regression) has been trained on a sample of 1456 rasterised images of the first 5 steps of random SK combinator expressions with varying leaf lengths, achieving 87.7% accuracy when classifying a test set of 1454 random SK combinator expressions as halting or non halting (before 40 steps).
This particular expression, which halts after 5 step(s), is classified as having a Indeterminate% probability of halting, and a Indeterminate% probability of not halting (before 40 steps).

Evaluated expression:
Halted in 4 step(s)
0k[s[k]][k[k[s]][s[s]]][s[s][k[s][s][k[k][s]][s[s[k][k]]][k[k]][s[s][k[s[k]]][s[k][k[s[s][k[k]]][k[s]]]][k[k[s][s[s[k][k]]]]]]]]
1s[k][s[s][s[k][s[s[k][k]]][k[k]][s[s[k][k[s[s][k[k]]][k[s]]]][k[s[k]][s[k][k[s[s][k[k]]][k[s]]]]][k[s]]]]]
2s[k][s[s][k[k[k]][s[s[k][k]][k[k]]][s[k][k[s[s][k[k]]][k[s]]][k[s]][k[s[k]][s[k][k[s[s][k[k]]][k[s]]]][k[s]]]]]]
3s[k][s[s][k[k][k[k[s]][k[s[s][k[k]]][k[s]][k[s]]][s[k][k[s]]]]]]
4s[k][s[s][k]]