Addresses are values that indicate where in the memory some other value is located. They can thus be used to pass around an indication of where to modify a value.
(at [address: (POINTER X)])
Returns the [X] value at [address]. The returned value can act as a
reference.
Examples: (at my_ptr_var), (at (ptr my_var))
Aliases: at.
(ptr [X])
Returns the address of [COMPUTATION VARIABLE].
Examples: (ptr my_var)
Aliases: address_of, addressof, addressOf, address, addr,
pointer_to, pointerto, pointerTo, pointer, ptr, reference_to,
referenceto, referenceTo, reference, ref.