Zill Library -

| Category | Examples | |----------|----------| | | dup , swap , drop , rot , over , nip | | Arithmetic | + , - , * , / , mod , inc , dec | | Comparison | = , < , > , <= , >= , and , or , not | | Lists/Sequences | cons , head , tail , length , map , fold , filter | | Strings | concat , length , split , join , to_upper | | I/O | put , putln , get , open , read , write | | Control | ifte (if‑then‑else), while , times |

: A signature feature of Zill’s texts is the focus on differential equations as models , explicitly discussing the constructs and potential pitfalls of each. zill library