Find readable with Permissions as POSIX? Aimed systems: Linux and OS X. Original code which works in Ubuntu 16.04 but not OS X, but follows unsuccessfully POSIX standards 

gfind ~ ! -readable -prune -o -type f -name "*.tex" 


where 


! is about Negation of a primary; the unary NOT operator.
-readable TODO this does not seem to be POSIX
-prune is about The primary shall always evaluate as true; it shall cause find not to descend the current pathname if it is a directory. If the -depth primary is specified, the -prune primary shall have no effect.
-o is about Alternation of primaries; the OR operator. The second expression shall not be evaluated if the first expression is true. That is if not, then this. 
-type about type, here file f
-name about filename, here *.tex


Output

gfind: paths must precede expression: type
Usage: gfind [-H] [-L] [-P] [-Olevel] [-D help|tree|search|stat|rates|opt|exec] [path...] [expression]


Fix proposal

Use -perm 0744 instead of -readable but not sure if it is equivalent

gfind ~ ! -perm 0744 -prune -o -type f -name "*.tex" 


Output: /Users/masi. Expected output: list of .tex files. 



How can you set permissions of find correctly for readable?
The double negation at the beginning makes this rather complex. Just using

gfind . -readable -type f -name '*.tex'


should work.

PS: Or find . -perm +0666 -type f -name '*.tex' for the default find.