Statement separator
Statement Separator (⋄) often called by the name of its glyph Diamond, allows you to place multiple statements on a single line. It works both inside a function and directly within the interpreter.
It is important to note that using a Statement Separator(⋄) forces the interpreter to read from left to right. Each separated statement will be read as if it is on it's own line.
When tracing errors within a line containing diamonds, statements to the right of the caret have not yet been executed.
In Iverson's Dictionary of APL [1] he states "expressions using the statement separator (⋄) can be mimicked by expressions using the verb left Identity. The primary difference is that the separation imposed by ⊣ follows the normal rules for order of execution." APL/700 uses a semicolon to achieve the same effect as the left tack (⊣).