File: EXPAND_CASES_CONV.doc

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\DOC EXPAND_CASES_CONV

\TYPE {EXPAND_CASES_CONV : conv}

\SYNOPSIS
Expand a numerical range {`!i. i < n ==> P[i]`}.

\DESCRIBE
When applied to a term of the form {`!i. i < n ==> P[i]`} for some {P[i]} and a 
numeral {n}, the conversion {EXPAND_CASES_CONV} returns 
{
  |- (!i. i < n ==> P[i]) <=> P[0] /\ ... /\ P[n-1]
}

\FAILURE
Fails if applied to a term that is not of the right form.

\EXAMPLE
{
  # EXPAND_CASES_CONV `(!n. n < 5 ==> ~(n = 0) ==> 12 MOD n = 0)`;;
  val it : thm =
    |- (!n. n < 5 ==> ~(n = 0) ==> 12 MOD n = 0) <=>
       (~(1 = 0) ==> 12 MOD 1 = 0) /\
       (~(2 = 0) ==> 12 MOD 2 = 0) /\
       (~(3 = 0) ==> 12 MOD 3 = 0) /\
       (~(4 = 0) ==> 12 MOD 4 = 0)

  # (EXPAND_CASES_CONV THENC NUM_REDUCE_CONV)
      `(!n. n < 5 ==> ~(n = 0) ==> 12 MOD n = 0)`;;     
  val it : thm = |- (!n. n < 5 ==> ~(n = 0) ==> 12 MOD n = 0) <=> T
}

\SEEALSO
NUM_REDUCE_CONV.

\ENDDOC