\DOC BETAS_CONV

\TYPE {BETAS_CONV : conv}

\SYNOPSIS
Beta conversion over multiple arguments.

\DESCRIBE
Given a term {t} of the form {`(\x1 ... xn. t[x1,...,xn]) s1 ... sn`}, the call
{BETAS_CONV t} returns
{
  |- (\x1 ... xn. t[x1,...,xn]) s1 ... sn = t[s1,...,sn]
}

\FAILURE
Fails if the term is not of the form shown, for some {n}.

\EXAMPLE
{
  # BETAS_CONV `(\x y. x + y) 1 2`;;
  val it : thm = |- (\x y. x + y) 1 2 = 1 + 2
}

\SEEALSO
BETA_CONV, RIGHT_BETAS.

\ENDDOC