NSPredicate表达评估

Question

我正在尝试使用NSPredicate来评估公式。但如果我更换 ＆安培;＆安培;与||反之亦然，评估失败。请找到代码段。

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
   NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

   NSString * str = @"( ( 10>5 || 10<5 ) && ('name' BEGINSWITH 'n') 
)";

   NSPredicate *p = [NSPredicate predicateWithFormat:str];

   BOOL passes = [p evaluateWithObject:nil];
   NSLog(@"passes: %@", passes ? @"yes" : @"no");


   [pool drain];
   return 0;
}

提前谢谢。