Fix #769, fix typos in base profile

index.bs

@@ -1839,7 +1839,7 @@ NOTE: This behavior is to allow future versions of this specification to define
 
 This section specifies the conformance points of the simple profile.
 
-When the [=primary_profile=] field set to 0, the following constraints apply to the [=IA Sequence=]:
+When the [=primary_profile=] field is set to 0, the following constraints apply to the [=IA Sequence=]:
 
 - There SHALL be only one unique [=Audio Element OBU=].
 - There SHALL NOT be any [=Temporal Delimiter OBU=]s present.
@@ -1856,8 +1856,8 @@ Capabilities of the IA parser, decoder, and processor:
 
 This section specifies the conformance points of the base profile.
 
-When the [=primary_profile=] field set to 1, the following constraints apply to the [=IA Sequence=]:
-- There SHALL be at most two unique [=Audio Element OBU=]s at any one time.
+When the [=primary_profile=] field is set to 1, the following constraints apply to the [=IA Sequence=]:
+- There SHALL be at most two unique [=Audio Element OBU=]s.
 	- There SHALL be at most one Channel-based [=Audio Element=] having [=num_layers=] > 1 at any one time.
 	- There SHALL be at most one Scene-based [=Audio Element=] at any one time.
 	- In other words, only the following combinations of two [=Audio Element=]s are allowed.