A block is a clause of statements grouped together.  Each IPL block begins
with a "{" (open brace) character and ends with a "}" (close brace).  It is
possible for a block to be empty and not contain any statements.

Each IPL program begins with a "{" character, which initializes the main
module block.  Execution continues until the final "}" block terminator is
reached (if the module hasn't been prematurely terminated).  An infinite
number of blocks may reside within the main block.

All procedures, functions, loops and conditional statements spawn blocks.
(Note that in some cases where there is only 1 statement, the open/close
brace characters are not necessary - as with the for/if/while commands.)

See also the @ reserved word for information on how variables are carried
through parent/child blocks.