regex explanation:
        The regular expression:

(?-imsx:s/\*/ && /)

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  s/                       's/'
----------------------------------------------------------------------
  \*                       '*'
----------------------------------------------------------------------
  / && /                   '/ && /'
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------
        The regular expression:

(?-imsx:s/\+/ || /)

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  s/                       's/'
----------------------------------------------------------------------
  \+                       '+'
----------------------------------------------------------------------
  /                        '/ '
----------------------------------------------------------------------
 |                        OR
----------------------------------------------------------------------
 |                        OR
----------------------------------------------------------------------
   /                       ' /'
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------
        The regular expression:

(?-imsx:s/(\w+)\s*'/!/g)

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  s/                       's/'
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    \w+                      word characters (a-z, A-Z, 0-9, _) (1 or
                             more times (matching the most amount
                             possible))
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
  \s*                      whitespace (\n, \r, \t, \f, and " ") (0 or
                           more times (matching the most amount
                           possible))
----------------------------------------------------------------------
  '/!/g                    '\'/!/g'
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------
        The regular expression:

(?-imsx:\((?:(?>[^()]+)|(??{$re}))*\))

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  \(                       '('
----------------------------------------------------------------------
  (?:                      group, but do not capture (0 or more times
                           (matching the most amount possible)):
----------------------------------------------------------------------
    (?>                      match (and do not backtrack afterwards):
----------------------------------------------------------------------
      [^()]+                   any character except: '(', ')' (1 or
                               more times (matching the most amount
                               possible))
----------------------------------------------------------------------
    )                        end of look-ahead
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    (??{$re})                run this block of Perl code (that isn't
                             interpolated until RIGHT NOW)
----------------------------------------------------------------------
  )*                       end of grouping
----------------------------------------------------------------------
  \)                       ')'
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------
processing DATA:

        -->received [a*b*!(c)]
        -->after first regex [a && b && !(c)]
        -->after second regex [a && b && !(c)]
        -->after third regex [a && b && !(c)]
        -->after fourth regex [a && b && !(c)]
        -->$term is [a && b && !(c)]
        @vars is [a b c]
        -->%vars is :
                $VAR1 = {
          'c' => 1,
          'a' => 1,
          'b' => 1
        };
        -->@vars is [a b c]
        -->$_ is [$a && $b && !($c)]

a b c = a && b && !(c)
        -->@vars is [$a $b $c]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
printf "$a $b $c = %d
", eval;
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
printf "$a $b $c = %d
", eval;
}}}]


0 0 0 = 0
0 0 1 = 0
0 1 0 = 0
0 1 1 = 0
1 0 0 = 0
1 0 1 = 0
1 1 0 = 1
1 1 1 = 0

        -->received [a'+b'+c']
        -->after first regex [a'+b'+c']
        -->after second regex [a' || b' || c']
        -->after third regex [!a || !b || !c]
        -->after fourth regex [!a || !b || !c]
        -->$term is [!a || !b || !c]
        @vars is [a b c]
        -->%vars is :
                $VAR1 = {
          'c' => 1,
          'a' => 1,
          'b' => 1
        };
        -->@vars is [a b c]
        -->$_ is [!$a || !$b || !$c]

a b c = !a || !b || !c
        -->@vars is [$a $b $c]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
printf "$a $b $c = %d
", eval;
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
printf "$a $b $c = %d
", eval;
}}}]


0 0 0 = 1
0 0 1 = 1
0 1 0 = 1
0 1 1 = 1
1 0 0 = 1
1 0 1 = 1
1 1 0 = 1
1 1 1 = 0

        -->received [!(a*b)]
        -->after first regex [!(a && b)]
        -->after second regex [!(a && b)]
        -->after third regex [!(a && b)]
        -->after fourth regex [!(a && b)]
        -->$term is [!(a && b)]
        @vars is [a b]
        -->%vars is :
                $VAR1 = {
          'a' => 1,
          'b' => 1
        };
        -->@vars is [a b]
        -->$_ is [!($a && $b)]

a b = !(a && b)
        -->@vars is [$a $b]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
printf "$a $b = %d
", eval;
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
printf "$a $b = %d
", eval;
}}]


0 0 = 1
0 1 = 1
1 0 = 1
1 1 = 0

        -->received [b^a]
        -->after first regex [b^a]
        -->after second regex [b^a]
        -->after third regex [b^a]
        -->after fourth regex [b^a]
        -->$term is [b^a]
        @vars is [b a]
        -->%vars is :
                $VAR1 = {
          'a' => 1,
          'b' => 1
        };
        -->@vars is [a b]
        -->$_ is [$b^$a]

a b = b^a
        -->@vars is [$a $b]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
printf "$a $b = %d
", eval;
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
printf "$a $b = %d
", eval;
}}]


0 0 = 0
0 1 = 1
1 0 = 1
1 1 = 0

        -->received [(a^b)']
        -->after first regex [(a^b)']
        -->after second regex [(a^b)']
        -->after third regex [(a^b)']
        -->after fourth regex [!(a^b)]
        -->$term is [!(a^b)]
        @vars is [a b]
        -->%vars is :
                $VAR1 = {
          'a' => 1,
          'b' => 1
        };
        -->@vars is [a b]
        -->$_ is [!($a^$b)]

a b = !(a^b)
        -->@vars is [$a $b]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
printf "$a $b = %d
", eval;
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
printf "$a $b = %d
", eval;
}}]


0 0 = 1
0 1 = 0
1 0 = 0
1 1 = 1

        -->received [(a+(a+b))'*c]
        -->after first regex [(a+(a+b))' && c]
        -->after second regex [(a || (a || b))' && c]
        -->after third regex [(a || (a || b))' && c]
        -->after fourth regex [!(a || (a || b)) && c]
        -->$term is [!(a || (a || b)) && c]
        @vars is [a a b c]
        -->%vars is :
                $VAR1 = {
          'c' => 1,
          'a' => 2,
          'b' => 1
        };
        -->@vars is [a b c]
        -->$_ is [!($a || ($a || $b)) && $c]

a b c = !(a || (a || b)) && c
        -->@vars is [$a $b $c]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
printf "$a $b $c = %d
", eval;
]
        -->$loops is [for $a (0..1) {
for $b (0..1) {
for $c (0..1) {
printf "$a $b $c = %d
", eval;
}}}]


0 0 0 = 0
0 0 1 = 1
0 1 0 = 0
0 1 1 = 0
1 0 0 = 0
1 0 1 = 0
1 1 0 = 0
1 1 1 = 0