_append(b1: binding, b2: binding): binding

Returns a binding formed by appending b2 to b1, but only if all the names in b1 and b2 are distinct. Otherwise, returns ERR.

_append([foo=1,bar=TRUE],[msg="a string",file="build.ves"])
    == [foo=1,bar=TRUE,msg="a string",file="build.ves"]

_append([], [msg="a string",file="build.ves"])
    == _append([msg="a string",file="build.ves"], [])
    == [msg="a string",file="build.ves"]

_append([foo=1], [foo="text",bar=TRUE]) == ERR                  // Duplicate name "foo"

_append(l1: list, l2: list): list

Returns a list formed by appending l2 to l1.

_append(<1,2>,<3,4>)
    == <1,2,3,4>

_append(<>, <1,2,3>)
    == _append(<1,2,3>, <>)
    == <1,2,3>