user7221: I investigated some Code examples, in haskell for Marlowe smart-contract, and used the "cabal repl" with the " :i " command, like this:
*Main> :i ValueEQ
type Observation :: *
data Observation = ... | ValueEQ Value Value | ...
-- Defined in ‘Language.Marlowe.Extended’
But I could not find the target library ‘Language.Marlowe.Extended’.
Is there a place where we can find the Haskell libraries for Marlowe?
There's perhaps also a haddock, like in Plutus, for Marlowe?

user907: What you are looking for is the repo where the Marlowe lang is implemented, more specifically the data constructor that you show is defined in the Observation data type:
data Observation = AndObs Observation Observation
                 | OrObs Observation Observation
                 | NotObs Observation
                 | ChoseSomething S.ChoiceId
                 | ValueGE Value Value
                 | ValueGT Value Value
                 | ValueLT Value Value
                 | ValueLE Value Value
                 | ValueEQ Value Value
                 | TrueObs
                 | FalseObs
  deriving stock (Show,Generic)
  deriving anyclass (Pretty)

Which is found in Language.Marlowe.Extended. So you can directly refer to the repo where the Haskell libraries are defined.

user7221: With some research, the Haskell libraries for Marlowe seems to be here precisely.

user342: Here are instructions for accessing Marlowe types and functions from ghci.

7221: <p>I investigated some Code examples, in haskell for Marlowe smart-contract, and used the &quot;cabal repl&quot; with the &quot; :i &quot; command, like this:</p>
<p>*<em>Main&gt; :i ValueEQ
type Observation :: *
data Observation = ... | ValueEQ Value Value | ...
-- Defined in ‘Language.Marlowe.Extended’</em></p>
<p>But I could not find the target library ‘Language.Marlowe.Extended’.</p>
<p>Is there a place where we can find the Haskell libraries for Marlowe?
There's perhaps also a haddock, like in Plutus, for Marlowe?</p>
 907: <p>What you are looking for is the <a href="https://github.com/input-output-hk/marlowe-cardano" rel="nofollow noreferrer">repo</a> where the Marlowe lang is implemented, more specifically the data constructor that you show is defined in the Observation data type:</p>
<pre><code>data Observation = AndObs Observation Observation
                 | OrObs Observation Observation
                 | NotObs Observation
                 | ChoseSomething S.ChoiceId
                 | ValueGE Value Value
                 | ValueGT Value Value
                 | ValueLT Value Value
                 | ValueLE Value Value
                 | ValueEQ Value Value
                 | TrueObs
                 | FalseObs
  deriving stock (Show,Generic)
  deriving anyclass (Pretty)
</code></pre>
<p>Which is found in <a href="https://github.com/input-output-hk/marlowe-cardano/blob/main/marlowe/src/Language/Marlowe/Extended.hs#L87" rel="nofollow noreferrer">Language.Marlowe.Extended</a>. So you can directly refer to the repo where the Haskell libraries are defined.</p>
 7221: <p>With some research, the Haskell libraries for Marlowe seems to be <a href="https://github.com/input-output-hk/marlowe-cardano/tree/main/marlowe/src/Language/Marlowe" rel="nofollow noreferrer">here</a> precisely.</p>
 342: <p><a href="https://github.com/input-output-hk/marlowe-cardano/blob/00c54fcf65ce18f82c580224f82f56b38e84bb68/doc/marlowe/tutorials/using-marlowe.rst" rel="nofollow noreferrer">Here</a> are instructions for accessing Marlowe types and functions from <code>ghci</code>.</p>
