$result = func1( $var++ ) op func2( $var );

##</code><code>##

sub read_a_line {return scalar <STDIN>}

##</code><code>##

my $two_lines = read_a_line() . read_a_line();

##</code><code>##

my $two_lines  = read_a_line();
   $two_lines .= read_a_line();

##</code><code>##

    EXPR1 OP EXPR2