| Precede (`le`) | Index << >>

| The comparison proceeds in the following order:
• | If the ranks differ, the lesser array is extended with leading 1-axes.
| If the resulting arrays match, the original ranks are used as a tie-breaker.
• | If the shapes differ, the arrays are extended to conform with fill items.
| If the resulting arrays match, the original shapes are used as a tie-breaker.
• | The arrays are compared item-wise in ravel order.
• | “Atomic” items are compared by type: char ≼ number ≼ ref ≼ `⎕OR` , where “atomic” means depth=0 or the`⎕OR` of a function, operator, or namespace.
• | Otherwise, if the types match:
| Characters are compared as now;
| Numbers are compared on their real part, followed by their imaginary part;
| Namespaces are compared , …
http://dfns.dyalog.com/n_le.htm