Attempted to make the instructions clearer

README.md

@@ -128,6 +128,9 @@ starknet-compile contracts/Evaluator.cairo
 
 ​
 ​
+### Step 3 - Set up your Solidity environmment
+The simplest way to develop and deploy Solidity contract is to use Remix:
+Navigate to https://remix.ethereum.org/ create a new file, compile it and deploy to Goerli using metamask 
 
 ## Working on the tutorial
 
@@ -146,7 +149,7 @@ To do this tutorial you will have to interact with the [`Evaluator.cairo`](contr
 
 ### Exercises & Contract addresses
 
-| Contract code                                                                                                                    | Contract on voyager                                                                                                                                                           |
+| Contract code                                                                                                                    | Contract on explorer                                                                                                                                                           |
 | -------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | [L2 Evaluator](contracts/Evaluator.cairo)                                                                                        | [0x595bfeb84a5f95de3471fc66929710e92c12cce2b652cd91a6fef4c5c09cd99](https://goerli.voyager.online/contract/0x595bfeb84a5f95de3471fc66929710e92c12cce2b652cd91a6fef4c5c09cd99) |
 | [Points counter ERC20](contracts/token/ERC20/TDERC20.cairo)                                                                      | [0x38ec18163a6923a96870f3d2b948a140df89d30120afdf90270b02c609f8a88](https://goerli.voyager.online/contract/0x38ec18163a6923a96870f3d2b948a140df89d30120afdf90270b02c609f8a88) |
@@ -161,27 +164,27 @@ To do this tutorial you will have to interact with the [`Evaluator.cairo`](contr
 
 ### Exercise 0 - Send an L2→L1→L2 message with existing contracts (2 pts)
 
-Use a predeployed contract to mint ERC20 tokens on L1 from L2. A secret message is passed with the messages; be sure to find it in order to collect your points.
+Use a predeployed contract to mint ERC20 tokens on L1 approved from L2. A secret is passed with the L2toL1 messages; be sure to find it in order to collect your points.
 
 - Call function [`ex_0_a`](contracts/Evaluator.cairo#L121) of [*L2 Evaluator*](https://goerli.voyager.online/contract/0x595bfeb84a5f95de3471fc66929710e92c12cce2b652cd91a6fef4c5c09cd99)
-  - You need to specify an L1 address, and an amount of ERC20 to mint
-  - The secret message is sent from L2 to L1 at this stage.
+  - You need to specify an L1 address of a user, and an amount of ERC20 to mint
+  - The secret message is sent from L2 to L1 within the message.
 - Call [`mint`](contracts/L1/DummyToken.sol#L37) of [*L1 DummyToken*](https://goerli.etherscan.io/address/0x0232CB90523F181Ab4990Eb078Cf890F065eC395)
   - You need to show that you know the secret value at this step
 - Call [`i_have_tokens`](contracts/L1/DummyToken.sol#L48) of [*L1 DummyToken*](https://goerli.etherscan.io/address/0x0232CB90523F181Ab4990Eb078Cf890F065eC395)
   - This function checks that you have indeed been able to mint ERC20 tokens, and will then send a message back to L2 to credit your points
-  - This is done using [`ex_0_b`](contracts/Evaluator.cairo#L143) of the L2 evaluator
+  - This message will be automatically handled by [`ex_0_b`](contracts/Evaluator.cairo#L143) of the L2 evaluator
 
 ### Exercise 1 - Send an L2→L1 message with your contract (2 pts)
 
 Write and deploy a contract on L2 that *sends* messages to L1.
 
-- Write a contract on L2 that will send a message to [L1 MessagingNft](https://goerli.etherscan.io/address/0x6DD77805FD35c91EF6b2624Ba538Ed920b8d0b4E) and trigger [`createNftFromL2`](contracts/L1/MessagingNft.sol#L35)
-  - Your function should be called [`create_l1_nft_message`](contracts/Evaluator.cairo#L198)
+- Write a contract on L2 that will send a message to [L1 MessagingNft](https://goerli.etherscan.io/address/0x6DD77805FD35c91EF6b2624Ba538Ed920b8d0b4E) and allow you to use [`createNftFromL2`](contracts/L1/MessagingNft.sol#L35) by consuming your message
+  - Your function should be called [`create_l1_nft_message`](contracts/Evaluator.cairo#L198) so that L2 Evaluator could trigger it properly
 - Deploy your contract
 - Submit the contract address to L2 Evaluator by calling its [`submit_exercise`](contracts/Evaluator.cairo#L166)
-- Call [`ex1a`](contracts/Evaluator.cairo#L188) of L2 Evaluator to trigger the message sending to L2
-- Call [`createNftFromL2`](contracts/L1/MessagingNft.sol#L35) of L1 MessagingNft to trigger the message consumption on L1
+- Call [`ex1a`](contracts/Evaluator.cairo#L188) of L2 Evaluator to trigger the message sending by your contract to L1
+- Call [`createNftFromL2`](contracts/L1/MessagingNft.sol#L35) of L1 MessagingNft to consumme message on L1
   - L1 MessagingNft [sends back](contracts/L1/MessagingNft.sol#L47) a message to L2 to [credit your points](contracts/Evaluator.cairo#L205) on L2
 
 ### Exercise 2 - Send an L1→L2 message with your contract (2 pts)
@@ -193,24 +196,24 @@ Write and deploy a contract on L1 that *sends* messages to L2.
   - You can get latest address of the StarkNet Core Contract Proxy on Goerli by running `starknet get_contract_addresses --network alpha-goerli` in your CLI
   - Learn how to get the [selector](https://starknet.io/docs/hello_starknet/l1l2.html#receiving-a-message-from-l1) of a StarkNet contract function
 - Deploy your contract
-- Trigger the message sending on L1. Your  points are automatically attributed on L2.
+- Use it to send a message to L2 Evaluator from L1. Your  points are automatically attributed on L2.
 
 ### Exercise 3 - Receive an L2→L1 message with your contract (2 pts)
 
-- Write a contract on L1 that will receive a message from  from function [`ex3_a`](contracts/Evaluator.cairo#L231).
+- Write a contract on L1 that will consumme a message from function [`ex3_a`](contracts/Evaluator.cairo#L231).
   - Make sure your contract is able to handle the message.
   - Your message consumption function should be called [`consumeMessage`](contracts/L1/Evaluator.sol#L51)
 - Deploy your L1 contract
 - Call [`ex3_a`](contracts/Evaluator.cairo#L231) of [*L2 Evaluator*](https://goerli.voyager.online/contract/0x595bfeb84a5f95de3471fc66929710e92c12cce2b652cd91a6fef4c5c09cd99) to send an L2→L1 message
-- Call [`ex3`](contracts/L1/Evaluator.sol#L32)of *L1 Evaluator*, which triggers message consumption from your L1 contract
+- Call [`ex3`](contracts/L1/Evaluator.sol#L32)of *L1 Evaluator*, which consumes a message from your L1 contract
   - L1 evaluator will also [send back](contracts/L1/Evaluator.sol#L57) a message to L2 to distribute your points
 
 ### Exercise 4 - Receive an L1→L2 message with your contract (2 pts)
 
-- Write a L2 contract that is able to receive a message from [`ex4`](contracts/L1/Evaluator.sol#L60) of [*L1 Evaluator*](https://goerli.etherscan.io/address/0x8055d587A447AE186d1589F7AAaF90CaCCc30179)
+- Write a L2 contract that is able to handle a message from [`ex4`](contracts/L1/Evaluator.sol#L60) of [*L1 Evaluator*](https://goerli.etherscan.io/address/0x8055d587A447AE186d1589F7AAaF90CaCCc30179)
   - You can name your function however you like, since you provide the function selector as a parameter on L1
 - Deploy your contract on L2
-- Call [`ex4`](contracts/L1/Evaluator.sol#L60) of *L1 Evaluator* to send the random value out to your L2 contract
+- Call [`ex4`](contracts/L1/Evaluator.sol#L60) of *L1 Evaluator* to send the random value out to your L2 contract and to L2 Evaluator
 - Submit your L2 contract address by calling [`submit_exercise`](contracts/Evaluator.cairo#L166) of *L2 Evaluator*
 - Call [`ex4_b`](contracts/Evaluator.cairo#L266) of *L2 Evaluator* that will check you completed your work correctly and distribute your points
 
@@ -256,7 +259,10 @@ You can (and should) check the status of your transaction with the following URL
 
 ### Articles & documentation
 
-- [Messaging Mechanism | StarkNet Docs](https://docs.starknet.io/docs/L1%3C%3EL2%20Communication/messaging-mechanism)
+- [Messaging Mechanism | StarkNet Docs](https://docs.starknet.io/documentation/architecture_and_concepts/L1-L2_Communication/messaging-mechanism/)
 - [Interacting with L1 contracts | StarkNet Documentation](https://starknet.io/docs/hello_starknet/l1l2.html)
 - Sample Project: [StarkNet graffiti | GitHub](https://github.com/l-henri/StarkNet-graffiti)
 - [Thread on StarkNet ⇄ Ethereum Messaging | Twitter](https://twitter.com/HenriLieutaud/status/1466324729829154822)
+- It is also usefull to bear in mind the following simplified schema:
+![alt text](https://github.com/panda4us/starknet-messaging-bridge/blob/main/images/simplified_messaging_schema.png?raw=true)
+