    [NAME]
    ALL.dao.control.if-else

    [TITLE]
    If-else Conditional Control

    [DESCRIPTION]

     0.1   Definition

       1  ControlBlock ::= Statement | '{' [ StatementBlock ] '}'
       2
       3  IfElseStmt ::= 'if' '(' [ LocalVarDeclaration ';' ] Expression ')' ControlBlock
       4                 { 'else' 'if' '(' [ LocalVarDeclaration ';' ] Expression  ')' ControlBlock }
       5                 [ 'else' ControlBlock ]

       1  a = 5
       2  if( a > 1 ) io.writeln( 'a > 1' )
       3
       4  if( a > 2 )
       5      io.writeln( 'a > 2' )
       6  else
       7      io.writeln( 'a <= 2' )
       8
       9  if( a < 3 )
      10      io.writeln( 'a < 3' )
      11  else if( a < 4 )
      12      io.writeln( 'a < 4' )
      13  else
      14      io.writeln( 'a >= 4' )