Update README.md

README.md

@@ -71,7 +71,7 @@ You can then run Daisy on an input file as follows:
 $ ./daisy testcases/rosa/Doppler.scala
 ```
 
-## Checking Error Bound Certificates
+## Generating Error Bound Certificates
 
 If you want to produce certificates to check them in either of the supported backends,
 you have to call Daisy as with
@@ -88,7 +88,7 @@ $ ./daisy file --certificate=binary
 ```
 The certificate can then be found in the folder `coq/output`, `hol4/output` or `output` for binary certificates.
 
-## Compiling the formal developments
+## Checking Coq certificates
 
 To check the Coq certificate, you need to enter the `coq` directory and then run
 ```bash
@@ -107,16 +107,35 @@ $ coqc -R ./ Daisy output/CERTIFICATE_FILE.v
 
 The generated binaries can be run with `coq_checker_{native/byte} CERTIFICATE_FILE`.
 
-To check the HOL4 certificate, you need to enter the `hol4` directory and then run
+## Checking HOL4 certificates
+
+If you haven't updated your HOL4 installation in a while, update it first:
+```bash
+$ cd path/to/HOL
+$ bin/build cleanAll
+$ poly < tools/smart-configure.sml
+$ bin/build
+```
+
+Then, back in the Daisy home directory, if you haven't done so before:
 ```bash
 $ git submodule init
+```
+(If successfull, you should see a message like ```Submodule 'hol4/cakeml' (https://github.com/CakeML/cakeml.git) registered for path 'hol4/cakeml'```)
+
+Then, initialize the CakeML submodule and start compilation:
+```bash
 $ git submodule update --recursive --remote
+$ cd hol4/
 $ Holmake
 ```
-to initialize the CakeML submodule and then start compilation.
-Note that this may take a lot of time, since it also builds all files from CakeML on which the extraction depends.
+Note that this may take some time, since it also builds all files from CakeML on which the binary code extraction depends.
+If you don't want to wait for so long, you can cheat the compilation:
+```bash
+$ Holmake --fast
+```
 
-To check the HOL4 certificates, you need to enter the `hol4/output` directory and then run
+To check the HOL4 certificates, enter the `hol4/output` directory and run
 ```bash
 $ Holmake ${CERTIFICATE_FILE/Script.sml/Theory.sig}
 ```