user14737: While contemplating both terms I could not find a difference between mental elaboration and mental fabrication. Aren't they one and the same?

user8157: The word 'sankhara' has an extremely wide diversity of meanings. For example, it is used in 'ayu sankhara', which means 'life force' (MN 43); or 'sankhara khandha', which means mental 'aggregate of thinking' (SN 22.79). A Buddha or Arahant has ayu sankhara (DN 16) & sankhara aggregate (SN 22.85) therefore 'sankhara' here does not inherently refer to something defiled or unwholesome. 
'Citta-sankhara' is perception & feeling (MN 44). It means that which conditions (sankhara) the mind (citta). For example, a pleasant feeling can condition the mind to have lust. An unpleasant feeling can condition the mind to have anger (MN 148). Thus 'citta-sankhara' means 'mind-conditioner'. Citta-sankhara is not sankhara khandha. Citta sankhara is vedana khandha (feeling aggregate) and sanna khandha (perception aggregate). 
Papanca is uncontrolled defiled mental proliferation (MN 18). Papanca is always unwholesome. Papanca is the activity of a defiled sankhara khandha. 
A Buddha does not produce 'papanca' because the sankhara aggregate of a Buddha is undefiled. A Buddha only deliberately generates pure thoughts, which are still 'sankhara' but are not 'papanca'.
You may refer this blog I wrote: The word ‘sankhara’ in context

user14609: yes it is not easy. First people  say that there are 2 triplets of sankaras : (kayasankhara, vacisankhara, mano sankhara) and (kayasankhara, vacisankhara, cittasankhara). they claim that they are not the same. See http://www.suttavinaya.com/wp-content/uploads/2018/07/Conditioned-Arising-of-Suffering-2018.pdf 
 Citta sankharas are vendana and sanna and they do not produce karma.
They claim that because they say that for instance, kaya sankhara  is the breath, but obviously the arhats still breath, therefore kayasankhara  still exists for the arhats.
Since they read that the arhats do not create karma, they infer that the kaya sankharas cannot be karmic.
The famous bikkhu analayo lists all those sankharas here https://www.buddhismuskunde.uni-hamburg.de/pdf/5-personen/analayo/encyclopedia-entries/sankhara.pdf
For papanca, people translate that as ''objectification'', like here 
https://www.accesstoinsight.org/tipitaka/an/an08/an08.030.than.html
https://www.accesstoinsight.org/search_results.html?cx=006639875531220445029%3A2z3mhfokk-u&ie=UTF-8&q=objectification&sa=Search
some say ''proliferation''. It means thinking this https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.047.than.html
https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.055.than.html

"He assumes feeling to be the self, or the self as possessing feeling,
  or feeling as in the self, or the self as in feeling.
"He assumes perception to be the self, or the self as possessing
  perception, or perception as in the self, or the self as in
  perception.
"He assumes (mental) fabrications to be the self, or the self as
  possessing fabrications, or fabrications as in the self, or the self
  as in fabrications.
"He assumes consciousness to be the self, or the self as possessing
  consciousness, or consciousness as in the self, or the self as in
  consciousness.
  "Now, there is the intellect, there are ideas (mental qualities),
  there is the property of ignorance. To an uninstructed run-of-the-mill
  person, touched by experience born of the contact of ignorance, there
  occur (the thoughts): 'I am,' 'I am thus,' 'I shall be,' 'I shall not
  be,' 'I shall be possessed of form,' 'I shall be formless,' 'I shall
  be percipient (conscious),' 'I shall be non-percipient,' or 'I shall
  be neither percipient nor non-percipient.'


14737: <p>While contemplating both terms I could not find a difference between mental elaboration and mental fabrication. Aren't they one and the same?</p>
 8157: <p>The word 'sankhara' has an extremely wide diversity of meanings. For example, it is used in '<em>ayu sankhara</em>', which means '<em>life force</em>' (MN 43); or '<em>sankhara khandha</em>', which means mental '<em>aggregate of thinking</em>' (SN 22.79). A Buddha or Arahant has ayu sankhara (DN 16) &amp; sankhara aggregate (SN 22.85) therefore 'sankhara' here does not inherently refer to something defiled or unwholesome. </p>

<p>'Citta-sankhara' is perception &amp; feeling (MN 44). It means that which conditions (sankhara) the mind (citta). For example, a pleasant feeling can condition the mind to have lust. An unpleasant feeling can condition the mind to have anger (MN 148). Thus '<em>citta-sankhara</em>' means '<em>mind-conditioner</em>'. Citta-sankhara is not sankhara khandha. Citta sankhara is vedana khandha (feeling aggregate) and sanna khandha (perception aggregate). </p>

<p>Papanca is uncontrolled defiled mental proliferation (MN 18). Papanca is always unwholesome. Papanca is the activity of a defiled sankhara khandha. </p>

<p>A Buddha does not produce 'papanca' because the sankhara aggregate of a Buddha is undefiled. A Buddha only deliberately generates pure thoughts, which are still 'sankhara' but are not 'papanca'.</p>

<p>You may refer this blog I wrote: <a href="https://dhammadhatu.wordpress.com/2016/06/13/the-word-sankhara-in-context/" rel="nofollow noreferrer">The word ‘sankhara’ in context</a></p>
 14609: <p>yes it is not easy. First people  say that there are 2 triplets of sankaras : (kayasankhara, vacisankhara, mano sankhara) and (kayasankhara, vacisankhara, cittasankhara). they claim that they are not the same. See <a href="http://www.suttavinaya.com/wp-content/uploads/2018/07/Conditioned-Arising-of-Suffering-2018.pdf" rel="nofollow noreferrer">http://www.suttavinaya.com/wp-content/uploads/2018/07/Conditioned-Arising-of-Suffering-2018.pdf</a> 
 Citta sankharas are vendana and sanna and they do not produce karma.
They claim that because they say that for instance, kaya sankhara  is the breath, but obviously the arhats still breath, therefore kayasankhara  still exists for the arhats.
Since they read that the arhats do not create karma, they infer that the kaya sankharas cannot be karmic.</p>

<p>The famous bikkhu analayo lists all those sankharas here <a href="https://www.buddhismuskunde.uni-hamburg.de/pdf/5-personen/analayo/encyclopedia-entries/sankhara.pdf" rel="nofollow noreferrer">https://www.buddhismuskunde.uni-hamburg.de/pdf/5-personen/analayo/encyclopedia-entries/sankhara.pdf</a></p>

<p>For papanca, people translate that as ''objectification'', like here 
<a href="https://www.accesstoinsight.org/tipitaka/an/an08/an08.030.than.html" rel="nofollow noreferrer">https://www.accesstoinsight.org/tipitaka/an/an08/an08.030.than.html</a></p>

<p><a href="https://www.accesstoinsight.org/search_results.html?cx=006639875531220445029%3A2z3mhfokk-u&amp;ie=UTF-8&amp;q=objectification&amp;sa=Search" rel="nofollow noreferrer">https://www.accesstoinsight.org/search_results.html?cx=006639875531220445029%3A2z3mhfokk-u&amp;ie=UTF-8&amp;q=objectification&amp;sa=Search</a></p>

<p>some say ''proliferation''. It means thinking this <a href="https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.047.than.html" rel="nofollow noreferrer">https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.047.than.html</a>
<a href="https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.055.than.html" rel="nofollow noreferrer">https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.055.than.html</a></p>

<blockquote>
  <p>"He assumes feeling to be the self, or the self as possessing feeling,
  or feeling as in the self, or the self as in feeling.</p>
  
  <p>"He assumes perception to be the self, or the self as possessing
  perception, or perception as in the self, or the self as in
  perception.</p>
  
  <p>"He assumes (mental) fabrications to be the self, or the self as
  possessing fabrications, or fabrications as in the self, or the self
  as in fabrications.</p>
  
  <p>"He assumes consciousness to be the self, or the self as possessing
  consciousness, or consciousness as in the self, or the self as in
  consciousness.
  "Now, there is the intellect, there are ideas (mental qualities),
  there is the property of ignorance. To an uninstructed run-of-the-mill
  person, touched by experience born of the contact of ignorance, there
  occur (the thoughts): 'I am,' 'I am thus,' 'I shall be,' 'I shall not
  be,' 'I shall be possessed of form,' 'I shall be formless,' 'I shall
  be percipient (conscious),' 'I shall be non-percipient,' or 'I shall
  be neither percipient nor non-percipient.'</p>
</blockquote>
