Some folks say that if they ... sneak... a gun into a business that has denied permission to enter to those who carry a gun that they are not breaking any laws. However....
https://www.law.cornell.edu/wex/trespass
Trespass
Trespass is defined by the act of knowingly entering another person’s property without permission. Such action is held to infringe upon a property owner’s legal right to enjoy the benefits of ownership. Criminal charges, which range from violation to felony, may be brought against someone who interferes with another person’s legal property rights. -snip-
Bold added by me for emphasis
By that definition a person who knows the property owner is denying permission to enter for those who carry a gun but .. sneak... in a gun anyway are engaging in the act of trespass.
There are laws that assess penalties to the act of trespass so the act of trespass is, or could be , (depending on the laws of the various States) breaking trespass law. So a person who is in the act of trespass is/could be breaking trespass law.
When the penalties for breaking trespass law and/or how the trespass law must be applied before penalties can be assessed depends on the laws of the various States.
But the point is... a person may not violate a firearms law (depends on the various States firearms laws) by ... sneaking... in a gun into property where those who carry a gun do not have the owner's permission but they still might be violating a trespass law.
And... when a person is asked to leave by the property owner or his representative isn't when the trespass happened.... the person was already in the act of trespass when the owner/representative caught them at it and asked them to leave. The getting caught/being asked to leave might (depends on various State laws) be the legal point where penalties will/could/might be assessed for the act of trespass.
So it might be a good idea to check your State's trespass laws before deciding to...sneak... a gun into/onto property that denies permission to those who carry guns.
And Axe, you said ... sneaking.... your gun in doesn't infringe upon the property owner's property rights?
https://www.law.cornell.edu/wex/trespass
Trespass
Trespass is defined by the act of knowingly entering another person’s property without permission.
Such action is held to infringe upon a property owner’s legal right to enjoy the benefits of ownership. -snip-
bold added by me for emphasis.