\input webmac
 \centerline{\bf Hello World}
 \vskip .5cm
 This is a very simple example of the WEB system.
 
 \M1. First, we define a text to be displayed.
 
 \Y\P$\4\X1:Content to print\X\S$\6
 \.{\'Hello,\ Literate\ Programming!\'}\par
 \U3.\fi
 
 \M2. This is the mainprogram of the Pascal program.
 An expression surrounded by $\langle$ and $\rangle$
 is substituted by its definition.
 
 \Y\P$\\{Program}\\{HelloWorld}(\\{output})$;\6
 \&{begin} \37\X3:Do something inside a program\X\6
 \&{end}.\par
 \fi
 
 \M3. You can define an identifier after reference in WEB language.
 \Y\P$\4\X3:Do something inside a program\X\S$\6
 $\\{writeLn}(\X1:Content to print\X)$\par
 
 \U2.\fi
 
 \inx
 \:\\{HelloWorld}, 2.
 \:\\{output}, 2.
 \:\\{Program}, 2.
 \:\\{writeLn}, 3.
 \fin
 \:\X1:Content to print\X
 \U3.
 \:\X3:Do something inside a program\X
 \U2.
 \con