I don't see how they arrive at the parsing table

grocery_stocker <cdalten@gmail.com>
Sat, 26 Apr 2008 15:48:16 -0700 (PDT)

From comp.compilers

Related articles
*I don't see how they arrive at the parsing table cdalten@gmail.com (grocery_stocker)* (2008-04-26)**
Re: I don't see how they arrive at the parsing table cdodd@acm.org (Chris Dodd) (2008-04-27)

From:	grocery_stocker <cdalten@gmail.com>
Newsgroups:	comp.compilers,comp.theory
Date:	Sat, 26 Apr 2008 15:48:16 -0700 (PDT)
Organization:	Compilers Central
Keywords:	LL(1), parse, question
Posted-Date:	27 Apr 2008 17:32:00 EDT

The question stems from the following URL

For the following grammar rules

1. S → F
2. S → ( S + F )
3. F → 1

They have a parsing table for ( 1 + 1 ) that looks like

    |( |) |1|+|$
__________
  S| 2| -|1|-| -
___________
  F|- |- |3|-| -

How do they arrive at this table? For example, they use first '(' from
the input stream. How do they know know to apply rule 2 and say not
rule 1?