[Question]
  [
I keep hearing that thinking outside the box is a goal worth achieving, but how can I tell if I'm successfully doing it?
To solve this dilemma I have already wrote a *Brainwave-to-ASCII*-translator which in theory should produce outputs like
```
                    #
   +------------+   #
   |   thinking |   #
   |            |   #
   +------------+   #
                    #
```
or
```
                   #
 +------+          #
 |      | thinking #
 |      |          #
 |      |          #
 +------+          #
                   #
```
which make it fairly easy to tell whether one is thinking outside the box or not. (The `#` are not part of the output and represent new lines.)
However, due to a bug sometimes only a smaller section of the output is returned:
```
   |         |         #
   +---------+         #
    thinking           #
```
```
        #
       +#
       |#
inking |#
```
```
    #
    #
```
## The Task
Please help me to automatically classify the *Brainwave-to-ASCII*-translator output by writing a program or function which reads an ascii-reprensentation and returns whether `thinking` is in the box, outside of it or it could not tell from the input.
### Input
A set of same-length strings either as a list or delimited by newlines containing
* the string `thinking` or valid pre- or suffixes thereof
* the characters `+-|` forming a rectangular box or valid parts of it
* spaces
* **NO `#`**, those are only included in the challenge to mark the ends of the input lines.
### Output
* a *truthy* value if `thinking` is outside the box
* a *falsy* value if `thinking` is in the box
* a distinct third *maybe* value if it can not be determined from the input whether `thinking` is in the box or not
## Examples
**Truthy:**
```
                   #
 +------+          #
 |      | thinking #
 |      |          #
 |      |          #
 +------+          #
                   #
```
```
   |         |         #
   +---------+         #
    thinking           #
```
```
        #
       +#
       |#
       |#
inking |#
```
```
thinking #
-------+ #
```
```
 ++ # (thinking is not in the box, so it must be outside)
 ++ # (this is also the smallest possible box)
```
```
+ #
 t#
```
 
```
+----+# (The box is not wide enough to contain "thinking")
```
```
---# (The box is not high enough to contain "thinking")
---#
```
As string input:
```
"                   \n +------+          \n |      | thinking \n |      |          \n |      |          \n +------+          \n                   "
"   |         |         \n   +---------+         \n    thinking           "
"        \n       +\n       |\n       |\ninking |"
"thinking \n-------+ "
" ++ \n ++ "
"+ \n t"
"+----+"
"---\n---"
"g++"
"k\n+"
```
**Falsy:**
```
                    #
   +------------+   #
   |   thinking |   #
   |            |   #
   +------------+   #
                    #
```
```
  +---------------#
  |               #
  |               #
  |   thinking    #
```
```
      | #
king  | #
------+ #
```
```
+---#
|thi#
+---#
```
```
-#
n#
-#
```
As string input:
```
"                    \n   +------------+   \n   |   thinking |   \n   |            |   \n   +------------+   \n                    "
"  +---------------\n  |               \n  |               \n  |   thinking    "
"      | \nking  | \n------+ "
"+---\n|thi\n+---"
"-\nn\n-"
```
**Maybe:**
```
thinking#
```
```
g|#
```
```
think#
-----#
```
```
|          |# (box large enough to possibly contain the string)
|          |#
```
```
   +--#
   |  #
```
```
# (empty input)
```
As string input:
```
"thinking"
"g|"
"|t"
"-\ni"
"h\n-"
"think\n-----"
"|          |\n|          |"
"   +--\n   |  "
""
```
## Rules
* This is [code-golf](/questions/tagged/code-golf "show questions tagged 'code-golf'"), so try to use as few bytes as possible.
* The *maybe* value can be chosen freely as long as it's different from the truthy/falsy value and is the same for all maybe-inputs. It can also be an error.
* You can assume that the input is always valid (eg. contains no other chars than `+-ghiknt|`, no more than one box, ...).
  
[Answer]
# Javascript (ES6), ~~274~~ 263 bytes
```
f=(a,b=(b,c="")=>a=a.replace(b,c),c=b=>b.test(`,${a},`))=>(b(/\w+/,5),b(/\+/g,1),b(/\-/g,2),b(/\|/g,3),b(/\n/g,4),c(/[13][2 ]{0,7}[13]|[12] *4 *[12]/)||(b(/ /g),b(/43+(?=4)/g),!c(/353|24542|12+435|21453|35412|5342+1/)&&(!c(/^([^1]*|([^15]*1){1,2}[^15]*)$/)||-1)))
```
The function `f` returns `true`, `false`, or `-1` as its "maybe" value. It should be called with one argument: the input. The other two parameters only exist to shorten the code.
Here's a less golfed version with comments:
```
var f = (input) => {
    var replace = (re, s) => input = input.replace(re, s);
    var test = re => re.test(input);
    /*
        Replace some "special" characters with ones that are shorter to put in a regex.
        "+" --> "1"
        "-" --> "2"
        "|" --> "3"
        "\n" --> ","
    */
    replace(/\+/g,1);
    replace(/\-/g,2);
    replace(/\|/g,3);
    replace(/\n/g,',');
    /*
        Shorten the word, if there is one, to just a single character "a".
    */
    replace(/[a-z]+/g,'a');
    /*
        Append a newline to the beginning and end of the input.
    */
    input = ','+input+',';
    /*
        Test the size of the box. These are the cases covered:
        /[13][2 ]{0,7}[13]/ : A horizontal edge or middle section has an inner width of fewer than 8 characters.
        /[12] *, *[12]/     : There are two horizontal edges in a row, with no space between.
        If either of these match, the word must be outside of the box. Return the truthy value (true).
    */
    if (test(/[13][2 ]{0,7}[13]|[12] *, *[12]/)) return true;
    /*
        Remove any spacing from the input. It it unnecessary from this point onwards.
    */
    replace(/ /g,'');
    /*
        Remove any lines with only vertical bars. These are also unnecessary.
    */
    replace(/,3+(?=,)/g,'');
    /*
        Edge / corner cases (heh). These are the cases covered:
        /3a3/    : two vertical bars with the word between.
        /2,a,2/  : two horizontal bars with the word between.
        /12+,3a/ : word inside the top left corner.
        /21,a3/  : word inside the top right corner.
        /3a,12/  : word inside the bottom left corner.
        /a3,2+1/ : word inside the bottom right corner.
        If any of these match, the word is inside the box. Return the falsy value (false).
    */
    if (test(/3a3|2,a,2|12+,3a|21,a3|3a,12|a3,2+1/)) return false;
    /*
        "Maybe" cases. These are the cases covered:
        /^[^1]*$/                : Input contains no corners, and may or may not contain a word.
        /^([^1a]*1){1,2}[^1a]*$/ : Input contains 1 or 2 corners, and no word.
        If either of these match, assuming the previous test cases have not been hit,
        we cannot tell if the word is inside or outside the box. Return the maybe value (-1).
    */
    if (test(/^([^1]*|([^1a]*1){1,2}[^1a]*)$/)) return -1;
    /*
        If none of the previous cases matched, the word must be outside of the box. Return the truthy value (true).
    */
    return true;
};
```
Had a lot of fun with this one. Thanks!
Edit: Saved 6 bytes thanks @L. Serné by modifying `b` to use a default argument, saving 3 bytes, and changing `[a-z]` to `\w`, saving 3 more bytes. Also saved 5 more bytes by making the word replacement non-global, saving 1 byte, and changing `"a"` to `5` and `","` to `4`, saving 4 bytes.
[Answer]
# Python 2.7, ~~532~~ ~~494~~ 453 bytes
This one sure had a lot of special cases. My truthy and falsy values are the strings "True" and "False" respectively. My maybe value is an Index Error, as they're easy to trigger and one of my test cases triggers it if the input is an empty string, which is a maybe case anyway. I made use of regular expressions quite a bit.
I don't golf in python often, so I'm sure this could be golfed down more, but here's my code:
```
import re
def e(s):exit(str(s))
i=input()
T=1<2
F=2<1
a=len(i)+1
c=i.count('+')
s='[a-z]'
x=re.search
p=x(s,i)
k=x('\+.*'+s,i)
l=x(s+'.*\|',i)
r=x('\|.*'+s,i)
f=i.find('+')
g=i[f-1]=='-'and f>0
if x('\-.*\n.*\-',i):e(T)
if x('\+.{0,7}\+',i):e(T)
if c>1 and not p:i[a]
if c>3:e(not(r and l))
if c>0:
 if r and l:e(F)
 if g:
    if l:e(F)
    if p or k:e(T)
    i[a]
 if r or k:e(F)
 if p:e(T)
 i[a]
if x('-.*\s[a-z].*\s-',i):e(F)
if x('\|.*[a-z].*\|',i):e(F)
i[a]
```
In my golfed version, I display the True/False answer by calling `exit(bool as string)`. Here's a commented version, in which the exit statements are replaced with return statements, and everything's been moved into a function:
```
import re
i=input()
T=True
F=False
def z():
    # some variables and shortcuts useful for testing
    # length of input +1. Used to throw an index out of bounds error on 'maybe'
    a=len(i)+1
    # c for i.Count()
    c=i.count
    # string used in regular expressions often
    s='[a-z]'
    # shorten regeX calls
    x=re.search
    # p is true is 'thinking' is Present on canvas
    p=x(s,i)
    # k is true if 'thinking' is Right of a 'Korner' (corner)
    k=x('\+.*'+s,i)
    # l is true if 'thinking' is Left of a pipe (|)
    l=x(s+'.*\|',i)
    # r is true if 'thinking' is right of a pipe
    r=x('\|.*'+s,i)
    # f is First corner (+) index
    f=i.find('+')
    # g is true if box is facing riGht (i.e. there is a dash before the first +)
    # for example, '---+' indicates the box faces right. if the + is the 0th
    # character, then the box must be facing left.
    # Note that this assignment also checks for the empty string 'maybe'
    # case, which is signalled by an IndexOutofBounds error
    # CASE 1: Empty Input
    # ex: ''
    g=i[f-1]=='-' and f>0
    # Begin testing all possible scenarios
    # CASE 2: Box is too short (vertically)
    # ex: ------
    #     ------
    if x('\-.*\n.*\-',i):return T
    # CASE 3: box is too short (horizontally)
    # ex: ||
    if x('\+.{0,7}\+',i):return T
    # CASE 4: box is not too short yet no corners (+) or text are present on canvas
    # ex:
    # |       |         --------
    # |       |   or
    # |       |         --------
    # this is a maybe case, so throw out of bounds error
    if c('+')>1 and not p:i[a]
    # CASE 5: Four corners visible (whole box visible)
    # ex: +---+
    #     | X |
    #     +---+
    # return false if text is both right of and left of pipes (i.e. in box)
    if c('+')>3:return not(r and l)
    # CASE 6: one or two corners visible
    # ex:
    # ----+        |    |          |
    #     |    or  +----+   or  ---+  etc
    # ----+
    # in this case, we idenify which way the box faces
    if c('+')>0:
        # CASE 6-A: Text is between two pipes
        # ex:
        #     |   X   |
        #     +-------+
        # if text is between pipes (box is extending from top or bottom of
        # canvas), then it is inside box
        if r and l:return F
        # CASE 6-B: Box faces right
        # if the box is riGht-facing, ex:
        # ----+
        #     |    or  ----+  etc
        # ----+            |
        if g:
            # CASE 6-B-a: Letters are left of a pipe or a + in a right facing box
            # ----+
            #  X  |   or  ----+
            # ----+         X |
            if l :return F
            # CASE 6-B-b: Letters are right of a pipe or + in a right facing box
            # ----+
            #     | X  or  ----+
            # ----+            | X
            if p or k:return T
            # CASE 6-B-c: right-facing otherwise
            # otherwise, it is a 'maybe' case
            # use an index out of bounds error to signal 'maybe'
            i[a]
        # CASE 6-C: Box faces left (or letters are on canvas yet not inside box)
        # ex:
        #   +----
        #   |        or   +---  or
        #   +----         |
        else:
            # CASE 6-C-a: Letters are right of a pipe or a + in a left facing box
            # if letters are right of pipe, they are inside box, ex:
            #   +----
            #   | X       or   +---  or X +---
            #   +----          | X        |
            if r or k:return F
            # CASE 6-C-b: Letters are left of a pipe in a left facing box
            # ex:
            #     +----
            #   X |        or     +---
            #     +----         X |
            # CASE 6-C-c: Letters are on canvas yet not left or right of
            # a pipe or a + (they must therefore be outside the box)
            # ex:
            #  |     |
            #  +-----+
            #     X
            if p:return T
            # CASE 6-C-d: text is not visible on canvas, and only part of the box is
            # ex:
            #  |     |
            #  +-----+
            #
            # this is a 'maybe' case, as text is off canvas
            # use an index out of bounds error to signal 'maybe'
            i[a]
    # CASE 7: No corners visible, nonempty input
    # CASE 7-A: No corners visible, letters sandwitched between dashes
    # ex:
    # -----
    #   X
    # -----
    # if there are no corners, yet letters are sandwitched between dashes,
    # then word is in box
    if x('-.*\s[a-z].*\s-',i):return F
    # CASE 7-B: No corners visible, letters sandwitched bewteen pipes
    # ex: |  X  |
    # in this case, word is inside box
    if x('\|.*[a-z].*\|',i):return F
    # If none of the above cases are met, it is a maybe, so throw the error
    i[a]
print z()
```
My solution assumes that the input is valid, i.e. 'Thinking' (or its substrings) are spelled correctly, there is only a single box, etc.
Edit: Saved 10 bytes thanks to @ais523's suggestion to change `c` to `i.count('+')`, 3 bytes thanks to @Pavel's suggestion of replacing `True` with `1<2` and `False` with `2>1`, 23 bytes by removing an unneeded else block, and 2 bytes by removing some spaces.
Edit 2: Saved 36 bytes thanks to @Wheat Wizard who kindly pointed out that my 'tabs' were actually 5 spaces (D'oh!) and suggested some other improvements.
[Answer]
# Befunge, 535 bytes
This isn't pretty, and doesn't come close to competing with the existing answers, but it's the best I could achieve in Befunge.
Returns `1` if thinking outside the box, `0` if thinking inside the box, and `-1` for *maybe*.
```
p10p20p130p140p150p9-:60p70p"~":80p90pvp8p04+1:g04p03:$p9g04+g9g\<<
0$$$$"xxxx"5p041p031p$_v#!-+55:_v#`0:~<p05+1g
v01g04$_v#*`\"|"\`"-"::<>0g\8\p"0"-!!40g1-\8\p:4-!:00g0`*!:00g\6\p40g\8\p00g!*4v
>p50g20p>8%:30g88+*+:3-v4v\-1g05!!*-"3"\-"4"::p\7\g05!!-3:+*+88g8g04:p00+g00*g0<
v!*-"3"\-"5"::p\6\g04!!<!>>7\p::"C"-\"3"-*!!50g\9\p"0"-!!50g1-\9\p:5-!:40g9g48*v
>!40g1-\6\p::"S"-\"3"-*!^>0#4g#p9#\g#94#\8#g*#0-#5!#p*#\5#70#\g#-*^#84g9g04:!*`<
>80g60g-8`90g70g-1`**+!:10g80g`60g10g`20g90g`70g20g`+++!!*\!-.@
^!g01***`"}"g09`"}"g08`g070`g060<
```
[Try it online!](http://befunge.tryitonline.net/#code=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&input=ICAgfCAgICAgICAgIHwgICAgICAgICAKICAgKy0tLS0tLS0tLSsgICAgICAgICAKICAgIHRoaW5raW5nICAgICAgICAgICA)
]