Fix some errors introduced by native speaker review

Signed-off-by: Pierre R. Mai <pmai@pmsf.de>

Author: pmai

doc/spec/binary_variables.adoc

@@ -40,7 +40,7 @@ The three actual variables shall contain an annotation of the following form in
 
 `<prefix>` is the prefix as defined above, and `@role` is either `base.lo`, `base.hi`, or `size`, depending on the variable.
 
-There is an error if there is not exactly one variable of each role for the same name.
+It is an error if there is not exactly one variable of each role for the same name.
 
 The MIME type given in `@mime-type` shall be a valid MIME type specification.
 

doc/spec/traffic_command_inputs.adoc

@@ -1,7 +1,7 @@
 = Traffic command inputs
 
 Traffic command inputs are present in traffic participant models.
-This makes it possible to control of the traffic participant behavior using scenario engines.
+This makes it possible to control the traffic participant behavior using scenario engines.
 
 **Prefix**
 
@@ -20,4 +20,4 @@ Traffic command inputs shall be named with the following prefix:
 * Each traffic command input shall be defined as a notional discrete binary input variable with `@causality="input"` and `@variability="discrete"`.
 * The MIME type of the variable shall specify the `type="TrafficCommand"` as part of the MIME type parameters.
 * Traffic commands shall be encoded as `osi3::TrafficCommand`.
-* The guaranteed lifetime of the traffic command protocol-buffer pointer provided as input to the FMU shall be from the time of the call to `fmi2SetInteger` that provides those values until the end of the following `fmi2DoStep` call.
+* The guaranteed lifetime of the traffic command protocol-buffer pointer provided as input to the FMU shall be from the time of the call to `fmi2SetInteger` that provides those values until the end of the following `fmi2DoStep` call.