.LP
Examples for using the IF-THEN-ELSE glyph to construct single
and double alternative decision structures within flow graphs.
.SH
If-Then
.LP
Example of a single alternative decision structure.  The execution of
the flow graph will terminate at the IF_ELSE glyph if the expression is
FALSE.
.LP
.DS L
.nf
\f(CW
                  ---------     Sequence of glyphs to
      Input   ----|=>   =>|----  be executed if the
     sequence     |       |      condition is TRUE  
                  |     =>|       
                  |if-else|
                  ---------
\fP
.fi
.DE
.SH
If-Then-Else
.LP
Example of a double alternative decision structure with divergent 
paths.
.LP
.DS L
.nf
\f(CW
                         --- Sequence of glyphs executed
            ---------   |     if the condition is TRUE
   Input ---|=>   =>|--- 
            |       |
            |     =>|--- 
            |if-else|   |
            ---------    --- Sequence of glyphs executed
                              if the condition is FALSE
\fP
.fi
.DE
.SH
If-Then-Else
.LP
Example of a double alternative decision structure with paths 
which rejoin (using the MERGE glyph).
.LP
.DS L
.nf
\f(CW
                       -- Sequence for TRUE --- 
           ---------  |                        |  ---------
   Input --|=>   =>|--                          --|=>   =>|
           |       |                              |       |
           |     =>|--                          --|=>     |
           |if-else|  |                        |  | merge |
           ---------   -- Sequence for FALSE --   ---------
\fP
.fi
.DE
